Patent Publication Number: US-7904652-B1

Title: Application aware use of added devices

Description:
BACKGROUND 
     1. Technical Field 
     This application generally relates to data storage, and more particularly to techniques used for data storage configuration and provisioning for use with different applications. 
     2. Description of Related Art 
     Computer systems may include different resources used by one or more host processors. Resources and host processors in a computer system may be interconnected by one or more communication connections. These resources may include, for example, data storage devices such as those included in the data storage systems manufactured by EMC Corporation. These data storage systems may be coupled to one or more servers or host processors and provide storage services to each host processor. Multiple data storage systems from one or more different vendors may be connected and may provide common data storage for one or more host processors in a computer system. 
     A host processor may perform a variety of data processing tasks and operations using the data storage system. For example, a host processor may perform basic system I/O operations in connection with data requests, such as data read and write operations. 
     Host processor systems may store and retrieve data using a storage device containing a plurality of host interface units, disk drives, and disk interface units. The host systems access the storage device through a plurality of channels provided therewith. Host systems provide data and access control information through the channels to the storage device and the storage device provides data to the host systems also through the channels. The host systems do not address the disk drives of the storage device directly, but rather, access what appears to the host systems as a plurality of logical disk units. The logical disk units may or may not correspond to the actual disk drives. Allowing multiple host systems to access the single storage device unit allows the host systems to share data in the device. In order to facilitate sharing of the data on the device, additional software on the data storage systems may also be used. 
     Different tasks may be performed in connection with a data storage system. For example, a customer may perform data storage configuration and provisioning tasks. Such tasks may include, for example, configuring and provisioning storage for use with an email application. Tasks may include allocating storage, specifying the logical and/or physical devices used for the storage allocation, specifying whether the data should be replicated, the particular RAID (Redundant Array of Independent or Inexpensive Disks) level, and the like. With such options in connection with performing configuration and provisioning tasks, a customer may not have the appropriate level of sophistication and knowledge needed. 
     Thus, it may be desirable to utilize a flexible technique which assists customers in connection with performing data storage management tasks such as related to data storage configuration and provisioning. It may be desirable that the technique be adaptable to the particular knowledge level of the user to provide for varying degrees of automation of data storage configuration and provisioning in accordance with best practices that may vary with the underlying data storage system and application. 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect of the invention is a method for configuring one or more physical devices of a data storage system for use in connection with provisioning storage for an application, the method comprising: receiving a policy including one or more sets of data storage system best practices, each of said one or more sets specifying data storage system best practices for a different type of data storage system including a first type associated with said data storage system; adding said one or more physical devices to said data storage system; and performing configuration processing in connection with configuring a first portion of said one or more physical devices for use with one or more storage pools, wherein said policy is used in performing said configuration processing. The method may include: automatically detecting, by said data storage system, said one or more physical devices; and in response to said automatically detecting said one or more physical devices, initiating said configuration processing. The first portion of said one or more physical devices may be configured for use with one or more storage pools automatically without user interaction. The step of performing configuration processing in connection with configuring a first portion of said one or more physical devices for use with one or more storage pools may further comprise: performing an interactive dialogue in accordance with a user proficiency level; obtaining one or more dialogue responses; and configuring said first portion of said one or more physical devices for use with one or more storage pools in accordance with said dialogue responses. The interactive dialogue may include obtaining information identifying one or more applications expected to host storage on said one or more physical devices. The first portion of said one or more physical devices may be added to one or more existing storage pools using said information obtained with said interactive dialogue. The first portion of said one or more physical devices may be configured into one or more new storage pools using said information obtained with said interactive dialogue. The configuration processing may include partitioning said first portion of said one or more physical devices into one or more storage pools, and the policy may indicate how to form said one or more storage pools from said one or more physical devices. The step of said configuration processing may further comprise: forming, in accordance with said policy and using said first portion of said one or more physical devices, one or more RAID groups each having a RAID configuration, said policy indicating a RAID level, said RAID configuration, and one or more physical device characteristics; defining, in accordance with said policy, one or more logical units of usable storage from each of said one or more RAID groups; defining, in accordance with said policy, one or more volumes of usable storage from said one or more logical units; and defining, in accordance with said policy, one or more storage pools from said one or more volumes of usable storage. Performing configuration processing in connection with initialization of said data storage system may include partially configuring a second portion of said one or more physical devices. Partially configuring may include configuring said second portion of said one or more physical devices only to a first configuration point at which one or more RAID groups are formed using said second portion of said one or more physical devices, and wherein, at said first configuration point, said second portion of said one or more physical devices are not configured into storage pools. The one or more RAID groups including said second portion of said one or more physical devices may be associated with one or more storage pools after storage is allocated in accordance with one or more provisioning requests subsequently received by the data storage system. The method may also include: detecting, by the data storage system, availability of a new policy at one of an external network location or a local device of the data storage system; and copying the new policy to the data storage system. 
     In accordance with another aspect of the invention is a method for configuring one or more physical devices of a data storage system for use in connection with provisioning storage for an application, the method comprising: receiving a policy including one or more sets of data storage system best practices, each of said one or more sets specifying data storage system best practices for a different type of data storage system including a first type associated with said data storage system; adding said one or more physical devices to said data storage system; and performing configuration processing in connection with partially configuring a first portion of said one or more physical devices for use with one or more storage pools, wherein said best practices for said first type of data storage system specified in said policy are used in performing said configuration processing. The policy may specify how to form a storage group of one of a plurality of types from one or more physical storage devices in accordance with best practices for said first type of data storage system, and wherein said policy may specify that said storage group of one of said types is formed from one of more RAID groups each having a RAID configuration. The policy may indicate a RAID level, said RAID configuration, and one or more physical device characteristics. The step of partially configuring may include configuring said first portion of said one or more physical devices only to a first configuration point at which one or more RAID groups are formed using said first portion of said one or more physical devices, and wherein, at said first configuration point, said first portion of said one or more physical devices are not configured into storage pools. 
     In accordance with another aspect of the invention is a data storage system comprising a computer readable medium with executable code stored thereon for configuring one or more physical devices of a data storage system for use in connection with provisioning storage for an application, the computer readable medium comprising code for: receiving a policy including one or more sets of data storage system best practices, each of said one or more sets specifying data storage system best practices for a different type of data storage system including a first type associated with said data storage system; initializing said data storage system; adding said one or more physical devices to said data storage system; performing, in accordance with said policy, configuration processing in connection with configuring a portion of said one or more physical devices for use with a plurality of storage pools, each of said plurality of storage pools specifying a generic storage resource formed from a first portion of physical devices of the data storage system; receiving, after completion of said configuration processing, a provisioning request to provision storage for an application; translating one or more application provision requirements of said provisioning request to generic storage resource requirements identifying one or more generic storage portions of said plurality of storage pools, wherein said translating is in accordance with application best practices for said application included in said policy; and implementing said provisioning request by allocating storage on said first portion of physical devices corresponding to said one or more generic storage portions. Each of said plurality of storage pools may be associated with a generic storage type. The generic storage type may be mapped to one or more properties of the data storage system in accordance with data storage system best practices of said first type for said data storage system. The data storage system best practices of said first type may define a first generic storage type formed from one or more physical devices of a first device type configured in accordance with a first RAID level and RAID configuration. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features and advantages of the present invention will become more apparent from the following detailed description of exemplary embodiments thereof taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is an example of an embodiment of a system that may utilize the techniques described herein; 
         FIG. 2  is an example representation of the mapping or translation processes that may be performed in an embodiment in accordance with the techniques herein; 
         FIG. 3  is an example representation of how storage pools may be configured from physical devices in an embodiment; 
         FIGS. 4 and 5  are examples illustrating use of the techniques herein in connection with provisioning storage for an application in an embodiment; 
         FIGS. 6 and 7  are flowcharts of processing steps that may be performed in connection with the techniques herein for provisioning storage in an embodiment; 
         FIGS. 8 and 9  are flowcharts of processing steps that may be performed in connection with the techniques herein when configuring physical storage devices for use in storage pools in an embodiment; 
         FIGS. 10 and 11  are examples representing information that may be included in a policy in an embodiment using the techniques herein. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENT(S) 
     Referring to  FIG. 1 , shown is an example of an embodiment of a computer system that may be used in connection with performing the techniques described herein. The computer system  10  includes one or more data storage systems  12  connected to server or host systems  14   a - 14   n  through communication medium  18 . The system  10  also includes a management system  16  connected to one or more data storage systems  12  through communication medium  20 . In this embodiment of the computer system  10 , the management system  16 , and the N servers or hosts  14   a - 14   n  may access the data storage systems  12 , for example, in performing input/output (I/O) operations, data requests, and other operations. The communication medium  18  may be any one or more of a variety of networks or other type of communication connections as known to those skilled in the art. Each of the communication mediums  18  and  20  may be a network connection, bus, and/or other type of data link, such as a hardwire or other connections known in the art. For example, the communication medium  18  may be the Internet, an intranet, network or other wireless or other hardwired connection(s) by which the host systems  14   a - 14   n  may access and communicate with the data storage systems  12 , and may also communicate with other components (not shown) that may be included in the computer system  10 . In one embodiment, the communication medium  20  may be a LAN connection and the communication medium  18  may be an iSCSI or fibre channel connection. 
     Each of the host systems  14   a - 14   n  and the data storage systems  12  included in the computer system  10  may be connected to the communication medium  18  by any one of a variety of connections as may be provided and supported in accordance with the type of communication medium  18 . Similarly, the management system  16  may be connected to the communication medium  20  by any one of variety of connections in accordance with the type of communication medium  20 . The processors included in the host computer systems  14   a - 14   n  and management system  16  may be any one of a variety of proprietary or commercially available single or multi-processor system, such as an Intel-based processor, or other type of commercially available processor able to support traffic in accordance with each particular embodiment and application. 
     It should be noted that the particular examples of the hardware and software that may be included in the data storage systems  12  are described herein in more detail, and may vary with each particular embodiment. Each of the host computers  14   a - 14   n , the management system  16  and data storage systems may all be located at the same physical site, or, alternatively, may also be located in different physical locations. In connection with communication mediums  18  and  20 , a variety of different communication protocols may be used such as SCSI, Fibre Channel, iSCSI, and the like. Some or all of the connections by which the hosts, management system, and data storage system may be connected to their respective communication medium may pass through other communication devices, such as a Connectrix or other switching equipment that may exist such as a phone line, a repeater, a multiplexer or even a satellite. In one embodiment, the hosts may communicate with the data storage systems over an iSCSI or a Fibre Channel connection and the management system may communicate with the data storage systems over a separate network connection using TCP/IP. It should be noted that although  FIG. 1  illustrates communications between the hosts and data storage systems being over a first connection, and communications between the management system and the data storage systems being over a second different connection, an embodiment may also use the same connection. The particular type and number of connections may vary in accordance with particulars of each embodiment. 
     Each of the host computer systems may perform different types of data operations in accordance with different types of tasks. In the embodiment of  FIG. 1 , any one of the host computers  14   a - 14   n  may issue a data request to the data storage systems  12  to perform a data operation. For example, an application executing on one of the host computers  14   a - 14   n  may perform a read or write operation resulting in one or more data requests to the data storage systems  12 . 
     The management system  16  may be used in connection with management of the data storage systems  12 . The management system  16  may include hardware and/or software components. The management system  16  may include one or more computer processors connected to one or more I/O devices such as, for example, a display or other output device, and an input device such as, for example, a keyboard, mouse, and the like. A data storage system manager may, for example, view information about a current storage volume configuration on a display device of the management system  16 , provision data storage system resources, and the like. 
     In one embodiment, the one or more data storage systems  12  of  FIG. 1  may be an appliance with hardware and software for hosting the data storage of the one or more applications executing on the hosts  14   a - 14   n . The appliance may include one or more storage processors and one or more devices upon which data is stored. The appliance may include software used in connection with storing the data of the hosts on the appliance and also software used in connection with configuring and provisioning the data storage for use by the hosts in connection with techniques described herein. As an example in connection with an email application server component that may executed on the hosts  14   a - 14   n , the data storage configuration and provisioning tasks may include allocating storage for user accounts or mailboxes, specifying the devices (logical and/or physical) used to store the email data, specifying whether data replication is performed for disaster recovery, configuring the physical devices in one or more RAID groups and other logical entities, and the like. Techniques that may be used in connection with performing data storage configuration, and configuration and provisioning tasks are described in more detail in following paragraphs in order to provide ease of use to customers of the data storage system(s)  12 . 
     In connection with an embodiment in which the data storage  12  is an appliance including hardware and software, the appliance may also include other software for performing different data services. For example, the appliance may include backup server software which interacts with software on the hosts  14   a - 14   n  when performing a backup operation. 
     In another embodiment, the data storage systems  12  may include one or more data storage systems such as one or more of the data storage systems offered by EMC Corporation of Hopkinton, Mass. Each of the data storage systems may include one or more data storage devices, such as disks. One or more data storage systems may be manufactured by one or more different vendors. Each of the data storage systems included in  12  may be inter-connected (not shown). Additionally, the data storage systems may also be connected to the host systems through any one or more communication connections that may vary with each particular embodiment and device in accordance with the different protocols used in a particular embodiment. The type of communication connection used may vary with certain system parameters and requirements, such as those related to bandwidth and throughput required in accordance with a rate of I/O requests as may be issued by the host computer systems, for example, to the data storage systems  12 . It should be noted that each of the data storage systems may operate stand-alone, or may also be included as part of a storage area network (SAN) that includes, for example, other components such as other data storage systems. Each of the data storage systems may include a plurality of disk devices or volumes. The particular data storage systems and examples as described herein for purposes of illustration should not be construed as a limitation. Other types of commercially available data storage systems, as well as processors and hardware controlling access to these particular devices, may also be included in an embodiment. 
     In such an embodiment in which element  12  of  FIG. 1  is implemented using one or more data storage systems, each of the data storage systems may include code thereon for performing the techniques as described herein for processing a data storage request to provision or configure data storage. 
     Servers or host systems, such as  14   a - 14   n , provide data and access control information through channels to the storage systems, and the storage systems may also provide data to the host systems also through the channels. The host systems may not address the disk drives of the storage systems directly, but rather access to data may be provided to one or more host systems from what the host systems view as a plurality of logical devices or logical volumes (LVs). The LVs may or may not correspond to the actual disk drives. For example, one or more LVs may reside on a single physical disk drive. Data in a single storage system may be accessed by multiple hosts allowing the hosts to share the data residing therein. An LV or LUN (logical unit number) may be used to refer to the foregoing logically defined devices or volumes. Data storage devices may also be configured using other logical device layers on top of the LV or LUN which are then exposed to the host or other component using the configured data storage. 
     In following paragraphs, reference may be made to a particular embodiment such as, for example, an embodiment in which element  12  of  FIG. 1  is an appliance as described above. However, it will be appreciated by those skilled in the art that this is for purposes of illustration and should not be construed as a limitation of the techniques herein. 
     Described in following paragraphs are techniques that may be used to assist customers of a data storage system in connection with performing data storage system management tasks such as related to data storage system configuration, provisioning of data storage, and the like. The techniques herein are adaptable to the particular knowledge level of the user. The techniques are flexible and allow for implementation of best practices and defaults in an automated fashion which are customized for the particular application, user or customer, and/or underlying data storage system and environment to meet specific customer needs. As will be described in more detail, depending on the level at which a user interacts with the data storage system, different levels or amounts of automation of the best practices may be performed. Depending on how the data storage system is configured, the user may elect to bypass the automation of best practices or limit the amount of automation performed by interacting with the system at various levels. User proficiency levels and exemplary embodiments are described in more detail in U.S. patent application Ser. No. 11/824,578, filed Jun. 29, 2007, APPLICATION AWARE STORAGE, which is incorporated by reference herein. 
     What will be described herein are techniques that may be used in connection with performing data storage configuration and provisioning of the data storage in connection with a request, for example, to allocate a portion of data storage for use with an application hosting data on a data storage system. 
     Referring to  FIG. 2 , shown is an example representation of the processing that may be performed in an embodiment in accordance with the techniques herein. The example  100  illustrates the processing that may be performed in connection with a request to provision storage of a data storage system for use by an application. For example, a provisioning request may be made to allocate storage for a number of mailboxes for use by an email application. The example  100  includes application provision requirements  102  which may be mapped or translated into generic storage resource requirements  104  in a first mapping or translation stage  120 . The generic storage resource requirements  104  may be mapped or translated into physical storage requirements  106  in a second mapping or translation stage  122 . The mapping stage  120  may be performed in accordance with application best practices. The steps comprising stage  120  may vary with each application. The mapping stage  122  may be performed in accordance with data storage specific best practices. The steps comprising stage  122  may vary with the particular underlying data storage system. 
     The application best practices implemented as part of  120  in an embodiment may be determined based on experience, know how, testing and the like, in connection with provisioning storage for a particular application. The data storage specific best practices implemented as part of  122  in an embodiment may be based on experience, know-how, testing, and the like, in connection with provisioning and configuring storage for a particular data storage system. To illustrate, the mapping performed in the first stage  120  may vary with a particular email application, database application, and the like. A different set of processing steps may be performed for each of the foregoing applications in accordance with the application best practices of each application. The mapping performed in the second stage  122  may vary with each data storage system provided by a same vendor or different vendor. For example, EMC Corporation provides the Symmetrix® data storage system and the CLARiiON® data storage system. A different set of processing steps may be performed for each of the foregoing data storage systems in accordance with data storage system specific best practices in connection with the second stage  122 . Both the application best practices and data storage system specific best practices may be codified in accordance with techniques herein to provide for automatically provisioning data storage system resources. An embodiment utilizing the techniques herein may implement the application and data storage system best practices using executable code which is executed on the data storage system when processing a request to provision storage and/or configure storage for use with the techniques herein. As will be described in more detail herein, the best practices may be codified using any one of a variety of different techniques known in the art such as, for example, using a script language, rules, programming language, and the like. Although reference may be made to particular ways in which the techniques herein may be implemented for purposes of example and illustration, such reference should not be construed as a limitation of the techniques herein. 
     Each of the different requirements  102 ,  104  and  106  and the two mapping stages  120  and  122  will now be described in more detail. 
     The application provision requirements  102  may specify the one or more provisioning requirements for a request. The requirements may make reference to application-specific terminology. The application provision requirements  102  may be the user inputs for the provisioning request received via a user interface (UI) using any one of a variety of different supported interfaces and techniques. The application provision requirements  102  may vary with user level and/or particular application for which the provisioning request is issued. 
     In one embodiment, the UI may provide for one or more different types of user interfaces and associated data. For example, the UI may provide support for a graphical user interface (GUI), command line interface (CLI), and the like. As also described herein, one or more different user levels may be provided in accordance with different levels of user proficiency. A user may interact with a system utilizing the techniques herein at any one of the user proficiency levels. The application provision requirements  102  may vary with each of the different user proficiency levels of interaction that may be provided in an embodiment. Each of the different user levels may provide a different logical view and level of abstraction with respect to a data storage task to be performed for an application executing on one of the hosts. Each of the different user levels may provide a different level of detail with respect to the underlying operations and tasks performed on the data storage system in accordance with different levels of user sophistication and knowledge. The language or terminology of the UI and application provision requirements  102 , UI data (e.g., content or data used to populate the UI menus), and UI presentation or structure (e.g., commands presented or particular hierarchical menu structure) may vary in accordance with the particular user level at which a user interacts with the data storage system as well as the application for which the provisioning request is being performed. Thus, a user may interact with the data storage system at a variety of different levels when issuing data storage configuration requests for the same application. The UI and application provision requirements may be customized for the particular level and application for which the request is performed. 
     In an embodiment, the application provision requirements  102  may be characterized as a set of application-specific requirements that may vary depending on the target user and associated user level at which the user may interact with the system. Thus, the application provision requirements  102  obtained in connection with a UI may vary with the user level and application. As described in more detail in following paragraphs, each user level may provide a different user interface and set of application provision requirements  102  for a different level of user interaction and level of knowledge and sophistication. Each user level may also be associated with a different level of automation of the application best practices, for example, with users interacting at a NOVICE level obtaining the greatest amount of automation of application best practices with an appropriate level of abstraction, and users interacting at other levels, such as INTERMEDIATE and EXPERT, obtaining a different appropriate level of abstraction and automation with respect to application best practices. 
     For example, a NOVICE user level may provide a beginner or most simplistic view of the data storage system and tasks performed for data storage configuration and provisioning in accordance with application best practices. NOVICE user level interactions require the least amount of knowledge and may be geared toward interacting with users having minimal knowledge when performing a data storage configuration or provisioning request by providing the greatest level of abstraction of the underlying system and operations performed. The language may be more non-technical in comparison to the interface language of other levels. As the user level increases (e.g., to INTERMEDIATE or EXPERT), so does the assumed level of knowledge of the user in connection with interactions. An EXPERT user level may be utilized by the most knowledgeable users providing a greatest granularity of control of all user levels in connection with a data provisioning request. The EXPERT user level may expose more detailed information to the user than interactions at NOVICE and INTERMEDIATE levels. As an example, a NOVICE level user may issue a request to provision storage for a number of mailboxes for storing data of an email application executing on one of the hosts. The NOVICE user may specify a minimal amount of information in connection with the request such as a number of mailboxes. A user may interface with the data storage system using a GUI and issue the data storage provision request. The language and terminology of user interactions via the GUI may be customized for the NOVICE user level of the email application. In connection with the same email application, a more knowledgeable user may choose to issue a data storage provision request via a GUI for a same number of mailboxes by interacting with the data storage system at an INTERMEDIATE or EXPERT level. For example, an EXPERT user level may provide a more detailed information about the request regarding the underlying data storage device and how this data storage device is used by the application. To further illustrate, the EXPERT level data storage provision request may specify additional application-specific information, the physical and/or logical devices upon which storage is allocated, provide vendor-specific or data storage-specific attributes or settings, indicate a number and type of files or data storage volumes created, and the like, that may vary with application for which storage is being provisioned. In connection with the type of file or volume for which storage is allocated, this may be particular to the email application. A file may be a database or a log file. The log files are used to keep a record of transactions taking place and may be used in connection with recovery operations. The database files hold mailbox stores such as email data. In connection with the NOVICE user level, the user may simply input a number of mailboxes and may omit additional detail such as specification of a number and size of database storage volumes, log volumes, and the like, as may be specified with an EXPERT level. For the NOVICE user level, such details may be specified as part of the mapping process  120  which maps the application provision requirements  102 , that may vary with user level, to generic storage requirements  104 . The defaults and other details in connection with the first mapping or translation stage  120  may be customized for the particular application in accordance with application best practices. 
     The application provision requirements  102  may be mapped in the first mapping or translation stage  120  to generic resource requirements in accordance with application best practices. Additionally, the first mapping or translation stage  120  may generate other output, such as application-specific information including application-specific attributes. The application-specific information may not be used in connection with the specifying generic storage resource requirements or otherwise involved in the second mapping or translation process. The application-specific information, and possible uses thereof, are described in more detail below. The application best practices may be a codified instance of  120  for each application. The generic storage resource requirements  104  may be characterized as an expression of the provisioning request in terms of application-neutral or application independent data elements and application independent data element properties. The generic storage requirements  104  refer to data elements that may be used as a common way of expressing the storage requirements for many different applications. In contrast, the application provision requirements  102  may make reference to data elements which are application-specific such as a number of mailboxes. The application-specific requirements of  102 , such as number of mailboxes, may be translated by  120  into application independent data elements that may be used as an intermediate expression of storage requirements for a provisioning request. As will be described in more detail in following paragraphs, generic storage requirements may refer to generic storage pools of storage volumes configured for use with servicing different application provisioning requests. For example, a storage pool of FAST storage may be defined. FAST storage may be defined as a general category of “fast” storage based on one or more different data storage system-specific properties which are used to characterize the storage pool and are used as part of the second mapping stage  122 . Such data storage specific properties may not be expressly or specifically included in the generic storage resource requirements  104 . Rather, the generic requirements of  104  may reference an abstract data storage element property of FAST based on one or more underlying data storage specific attributes. The particular properties and associated values used to define a FAST storage pool as well as other storage pools may vary with the underlying data storage system and associated data storage system best practices. A portion of storage from one of the storage pools, such as a volume or portion thereof, may be used in specifying generic data storage resource requirements  104 . As another example, an embodiment may define one or more CHEAP storage pools along with one or more FAST storage pools for use in connection with specifying generic resource requirements  104 . As with FAST storage pools, CHEAP may be an abstract data storage element property based on one or more data storage specific properties and values that vary with the underlying data storage system. The particular properties and values used to characterize and define a CHEAP storage pool may vary with data storage system and associated data storage system best practices. CHEAP may refer to a second type of data storage which may be characterized as inexpensive and not as fast in connection with servicing I/O requests relative to the storage pools of type FAST. In contrast to CHEAP storage pools, storage pools of type FAST may consist of faster device types and device configurations which may typically result in faster I/O request service times. Other embodiments may use a different number and different types or categories of storage pools other than FAST and CHEAP. In one embodiment as described herein, the generic storage resource requirements may be expressed in terms of generic data storage elements, such as storage pools and portions thereof, having one generic data storage element properties, such as FAST or CHEAP. 
     As described above, the first mapping or translation stage  120  may output generic storage resource requirements and also application-specific information or application specific attributes. The application-specific information may be characterized as additional attributes associated with the generic storage resource requirements but which are not used in connection with the second mapping stage  122 . The generic storage resource requirements are mapped in the second mapping stage  122 , but not the application-specific information is not utilized. The application-specific information may be used to provide additional information regarding the generic provisioned storage for other purposes. For example, the application-specific information may be used in connection with further annotating provisioned storage and presenting the information to a user. The application-specific information may be used in annotating other information maintained and used for other purposes than the second mapping stage  122  as described herein. For example, the application-specific information may include application-specific attributes associated with data objects of a data model used in presenting information on currently allocated and provisioned storage to the user. As such, the first mapping stage  120 , in addition to producing the generic storage resource requirements, may produce other types of outputs used in connection with other processing operations, tasks, and data models. 
     The generic storage resource requirements  104  may be mapped by the second mapping or translation stage  122  into physical data storage requirements  106 . The requirements  106  may vary with the particular type of data storage system (e.g., different data storage system by same or different vendor), customer&#39;s configuration and data storage environment (e.g., which data storage system types, number of each, vendor), number and type of devices on each data storage system (e.g., disks, disk or other device characteristics such as capacity, number of disks), and the like. The requirements  106  identify data storage system resources used in connection with implementing or fulfilling a request to provision storage for use by the application. Such resources may include the one or more physical devices from which storage is allocated for use in storing data and any parity information. In an embodiment in which the data storage system is a multiprocessor architecture, a designated processor of the data storage system may be assigned to service I/O requests for one or more portions of the allocated storage. The processing of stage  122  maps the generic requirements of  104  in accordance with the different data storage specific properties that may be associated with each storage pool to the physical resources of the data storage system. As an example, each storage pool may be formed from one or more different RAID groups of physical devices. A provision request for a volume of storage in a storage pool is mapped to a portion of physical storage in accordance with the data storage best practices codified in  122 . With reference to the generic storage requirements  104  that may refer to a volume in a FAST or CHEAP storage pool, data storage system best practices may determine how FAST and CHEAP are defined for each type of data storage system. 
     In connection with the techniques herein, an embodiment implementing application best practices does not have to have any knowledge regarding the underlying data storage system and data storage system best practices. In other words, the application best practices and the data storage best practices may be developed independently of one another in accordance with the techniques herein. As a result, an instance of an application best practice implemented as part of  120  may be used with any one or more different implementations of data storage best practices of  122 . Similarly, an instance of data storage best practices  122  may be used with any one or more different implementations of application best practices of  120  for different applications. 
     Thus, using the techniques herein, an embodiment may define a first FAST storage pool and a first CHEAP storage pool using data storage on a Symmetrix® data storage system. The embodiment may also define a second FAST storage pool and a second CHEAP storage pool using data storage on a CLARiiON® data storage system. A same application may host data storage using the techniques herein on both the CLARiiON® data storage system and the Symmetrix® data storage system. A first code module, such as a first script, may be used to perform the first mapping stage  120  in accordance with the application best practices. A second code module, such as a second script, may be used to perform data storage specific mapping of  122  for the Symmetrix® data storage system. A third code module, such as a third script, may be used to perform data storage specific mapping of  122  for the CLARiiON® data storage system. Both the second and third scripts may be used with the first script in an embodiment in accordance with the techniques herein. 
     To further illustrate with respect to  FIG. 2 , the application provision requirements may have an application-specific focus and provide a level of abstraction customized for an application such as, for example, a particular email application, law office application or medical office application, as well as a class of related applications, such as a multiple email applications. The application provision requirements may vary with the particular application as well as user level. The interface language may vary with the application. For example, if the application is a law office application, the interface language, menu options, and the like, may be tailored to the law profession and particular law office application. Similarly, a medical office application may utilize an interface language, menu options, and the like, familiar to the medical office and for the particular medical application. As such, the first mapping or translation step  120  may use one set of rules, mappings, script, and the like, for each application to implement the application specific best practices for the one or more provided user levels. For example, a first script for the medical office application may be used to map the user input parameters using medical office terminology to the generic storage requirements  104 . A second script for the law office application may be used to map the user input parameters using law office terminology to generic storage resource requirements  104 . The user connecting to the data storage system may be provided with a UI customized for the selected level and application to perform a requested data storage configuration. The requirements  102  obtained using the UI may vary with the user level. 
     The generic storage resource requirements  104  may not be tailored for any particular application. In other words, the generic storage resource requirements specifies a common terminology (e.g., data elements, model, properties, etc.) for expressing provision requests for multiple applications such as the medical application, law office application, email application, database application, and the like. The requirements  104  are mapped to physical data storage requirements  106  using second mapping or translation processing defined by data storage system best practices codified as part of  122 . The physical data storage system requirements  106  may be customized for the particular storage vendor and associated options. For example, the requirements  106  may be specified in terms of particular physical data storage devices and attributes, RAID levels and techniques, SCSI and iSCSI terminology, vendor-specific options, and the like. The best practices and the automation of the best practices as described in more detail in following paragraphs may be customized for a particular application and the particular data storage system and environment. 
     A policy may be defined in an embodiment in accordance with the best practices for applications and data storage systems. A policy may be characterized as an instantiation of the application practices and/or data storage system best practices in an embodiment. A policy including application best practices may specify defaults used in connection with the different user levels for one or more applications. For example, for an email application, the policy may specify a default amount of mailbox data storage capacity and log storage capacity for each mailbox or group of mailboxes, may indicate that mailbox data is stored on FAST storage and that log data is stored on CHEAP storage, and may also specify other application independent or application-neutral criteria that may be used in servicing the provisioning request. The other criteria may include whether the data storage for the application should be allowed to share a RAID group with a different application thus affecting I/O performance, whether the storage needs to be expandable for use with the application&#39;s future storage needs, an expansion factor or amount indicating a threshold minimum amount of available storage for use with future data storage needs of the application, and the like. A policy including data storage system best practices may define CHEAP and FAST for each type of data storage system. For example, an embodiment may specify a data storage system best practices policy for a first type of data storage system in which FAST is defined as using Fibre Channel drives, a RAID-10 configuration of device pairs, and assigning servicing of I/O requests by a particular data storage system service processor since the first type of data storage system is a multi-processor architecture. For a second type of data storage system, FAST may be defined as using Fibre channel drives, and a RAID-5 (4 data drives+1 parity drive) configuration. The second type of data storage system does not include multiple data storage system service processors for servicing I/O requests thus no data storage service processor assignment is made. If the second type of data storage system does not support use of Fibre channel drives but rather uses a different form of storage or other device having high speed performance characteristics, then such a device may be specified rather than the Fibre channel devices. Different elements that may be included in a policy are described herein in more detail. 
     The physical storage devices of the data storage system may be configured or partitioned into storage pools for use in connection with specifying generic requirements of  104 . An embodiment may form one or more such storage pools for use in connection with servicing a provisioning request prior to the issuance of the provisioning request. In other words, the physical storage devices may be configured into one or more storage pools at a first point in time. At a second later point in time, storage may be allocated from the previously formed storage pools in connection with a provisioning request to allocate storage for use with an application hosting data on the data storage system. As will be described in more detail herein, storage pools may be formed at different points in time in connection with the life cycle of a data storage system and a defined policy. For example, storage pools may be formed as part of data storage system initialization and startup processing and when new data storage devices are added to a data storage system. An embodiment may also form storage pools as part of processing in response to receiving a provisioning request. Examples of the foregoing and different variations of how and when storage pools may be formed are described in more detail herein. 
     Referring to  FIG. 3 , shown is an example representing how data storage system best practices may be used to form storage pools. The example  150  illustrates how storage pools may be constructed from groups of physical devices. For example, RAID Group 1  154   a  may be formed from physical devices  152   a . The data storage system best practices of a policy may specify the particular RAID level and configuration for the type of storage pool being formed. For example, for physical devices  152   a  on a first data storage system type when forming a FAST storage pool, RAID-5 may be used in a 4+1 configuration (e.g., 4 data drives and 1 parity drive). The RAID Group 1  154   a  may provide a number of data storage LUNs  156   a . An embodiment may also utilize one or more additional logical device layers on top of the LUNs  156   a  to form one or more logical device volumes  158   a . The particular additional logical device layers used, if any, may vary with the data storage system. It should be noted that there may not be a 1-1 correspondence between the LUNs of  156   a  and the volumes of  158   a . In a similar manner, device volumes  158   b  may be formed or configured from physical devices  152   b . The storage pool  1  of the example  150  illustrates two RAID groups being used to define a single storage pool although, more generally, one or more RAID groups may be used for form a storage pool in an embodiment using RAID techniques. 
     The data storage system best practices may define how to configure or form the generic storage pools, each storage pool having an associated generic storage pool type.  FIG. 3  illustrates one methodology or framework that may be used to form storage pools in an embodiment. In an embodiment following the methodology of  FIG. 3 , each underlying data storage system may have associated best practices specifying how to configure storage pools formed from physical devices in that particular data storage system. For example, as described elsewhere herein in more detail, different data storage systems may have varying best practices in connection with forming a FAST or CHEAP RAID group. 
     For purposes of illustration in an example that will now be described, the storage pools used in connection with servicing a provisioning request for storage for an application may be formed prior to the issuance of the provisioning request. However, as will also be described in more detail elsewhere herein, processing performed to configure physical devices into storage pools may be performed at other points in time. 
     Referring to  FIG. 4 , shown is an example illustrating use of the techniques herein with the two stage mapping processing as described in connection with  FIG. 1 . The example  200  includes application provision requirements  202  which are input in connection with a NOVICE user proficiency level for an email application hosting storage on the data storage system. In this example, the requirements of  202  include a server name, such as “SERVER1”, and a number of mailboxes, such as 500. The user may be requesting that storage be allocated for 500 mailboxes for use with an email application. The application best practices for the email application may be codified using a script, rules, programming language, and the like, which map the requirements of  202  to the generic storage resource requirements of  204 . In this example, the element  204  includes the generic storage resource requirements further annotated with application specific information as will be described in more detail below. In an embodiment, one or more candidate solutions or ways in which the resource provisioning request may be serviced may be specified in terms of the generic resource requirements. The example  200  illustrates two possible or candidate solutions  204   a  and  204   b . For each of these candidate solutions, the currently available resources of the data storage system may be examined to see if the provisioning request may be implemented in accordance with each candidate solution. In other words, each candidate solution specifies amounts and types of data storage needed to fulfill the current provision request. The current state of available resources on the data storage system is examined to determine if it is possible to allocate resources as needed for each candidate solution. It may be that there are insufficient resources available on the data storage system so that one or more candidate solutions are eliminated. In this example, candidate solution  204   a  indicates that 5 storage groups (SGs) may be formed in which each SG consists of storage for 100 mailboxes. Each SG may include 2 volumes of FAST storage of capacity SIZE1 for storing mail data, and 1 volume of CHEAP storage of capacity SIZE2 for logging purposes. Both of the foregoing are stored on storage which is PROTECTED or provides data protection in the event of device failure. Data protection may be a generic way of specifying some form of data redundancy such as mirroring, or other technique (e.g., RAID protection via parity information) by which data recovery is possible in the event of a data device failure. Candidate solution  204   b  indicates that a single SG may be formed consisting of storage for all 500 mailboxes. The SG may include 10 volumes of FAST storage of capacity SIZE1 for storing mail data, and 5 volumes of CHEAP storage of capacity SIZE2 for logging purposes. In connection with solution  204   b , additional CRITERIA may be specified of OWN GROUP. In one embodiment, OWN GROUP may be used to indicate that the storage allocated for use by the email application should be from a RAID group which does not share storage with any other application. Such criteria may affect the performance of servicing I/O requests for each application hosting data included in the same RAID group. In another embodiment, OWN GROUP may indicate that the data storage in connection with this single provisioning request should be in its own RAID group so that these particular 500 mailboxes do not share a same RAID group with other mailboxes for this email application or another application. 
     As described above, the first mapping or translation stage  120  may output generic storage resource requirements and also application-specific information as included in  204   a  and  204   b . With reference to  204   a , the generic resource requirements may include the following information describing generic storage allocated for each of 5 storage groups (SGs):
         2 Volumes FAST SIZE1, 1 volume CHEAP SIZE2, PROTECTED, CRITERIA=OWN GROUP       

     In other words, 5 sets of the foregoing generic storage volumes are allocated, each set being associated with storage provisioned for a different SG. The SG associations may be expressed in the application-specific attributes described below. 
     The remaining information of element  204   a  may be application specific information. For example, application specific information of  204   a  may include information regarding the fact that 5 storage groups (SGs) are formed, each SG contains 100 Mboxes (mailboxes), and also that each SG consists of a particular number and type of generic storage volume (e.g., 2 FAST volumes and 1 CHEAP volume). In other words, the SG application-specific attribute may be associated with particular instances of provisioned generic storage. Furthermore, each generic FAST storage volume may be associated with an application specific attribute of “Data” (e.g., an application specific attribute of “Data” occurs in “2 Volumes FAST SIZE1 Data, PROTECTED”). Each generic CHEAP storage volume may be associated with an application specific attribute of “Log” (e.g., an application specific attribute of “Log” occurs in “1 volume CHEAP SIZE2 Log, PROTECTED”). The attributes of Data and Log, along with the SG attribute, may be particular to the email application and used to annotate or further describe information maintained in a data model for other uses such as presenting information on provisioned storage for different applications to a user. 
     With reference to  204   b , the generic resource requirements may include the following information:
         10 volumes FAST SIZE1, 5 volumes CHEAP SIZE2, PROTECTED CRITERIA=OWN GROUP       

     The remaining information of element  204   b  may be application specific information. For example, application specific information of  204   b  may include information regarding the fact that 1 storage groups (SGs) is formed containing all 500 mailboxes and that the single SG consists of particular generic storage data elements such as 10 FAST volumes and 5 CHEAP volumes. Each FAST volume in this example may be associated with an application specific attribute of “Data” (e.g., an application specific attribute of “Data” occurs in “10 Volumes FAST SIZE1 Data, PROTECTED”). Each CHEAP volume in this example may be associated and an application specific attribute of “Log” (e.g., an application specific attribute of “Log” occurs in “5 volumes CHEAP SIZE2 Log, PROTECTED”). 
     Element  210  may represent the different storage pools configured from the physical devices of the data storage system. In other words, element  210  may represent the different storage pools configured from the physical devices as illustrated in  FIG. 3  in accordance with data storage system best practices for a currently defined policy. Element  210  includes FAST storage pool A of SIZE X, and FAST storage pool A 2  of SIZE X 1 . Element  210  may also include CHEAP storage pool B of SIZE Y. For purposes of illustration, a policy may be in effect which defines FAST storage as preferably formed from Fibre channel devices with a RAID-10 configuration of pairs of physical devices for mirroring, and CHEAP storage formed from ATA (Advanced Technology Attachment) devices with RAID-5 having 8 data drives and 1 parity drive (8+1). At data storage system startup time, FAST storage pool A and CHEAP storage pool B may be configured. At a first later point in time, 5 more Fibre channel drives may be added to the data storage system for additional storage capacity and processing may be performed to configure these 5 drives into storage pools for use with the techniques herein. In accordance with data storage system best practices, although RAID 10 may be preferred over other RAID levels and configurations, the data storage system best practices may note that 5 drives have been added and thus, to make use of all 5 drives, a RAID 5 configuration of 4 data drives and 1 parity drive may be preferred in this particular instance with the addition of an odd number of 5 drives. As such, the code implementing the data storage system best practices may result in formation of the FAST storage pool A 2 . It should also be noted in this example that the data storage system for which the foregoing best practices are defined may be a multiprocessor architecture so that a different data storage system processor may be assigned to service I/O requests in accordance with the FAST or CHEAP storage pool type. In this example, data storage system processor A may be used to service I/O requests for the FAST storage pools and processor B may be used to service I/O requests for the CHEAP storage pool. It may known that processor A may be used to only service the FAST storage pool and processor B may used to service the CHEAP storage pool as well as perform other processing tasks in the data storage system. Thus, such a processor assignment may serve as a factor in the I/O processing rate for the FAST storage pools being higher than that associated with the CHEAP storage pool. In connection with  210 , FAST storage pool A currently has SIZE X amount of storage capacity available for use, FAST storage pool A 2  currently has SIZE X 1  amount of storage capacity available for use, and CHEAP storage pool B currently has SIZE Y amount of storage capacity available for use. Additional properties for each storage pool are indicated in area  210   b.    
     For each candidate solution  204   a  and  204   b , the different storage pools, currently available data storage capacity, and associated properties of  210   b  are examined in accordance with the following for each candidate solution: the type of storage (e.g, FAST or CHEAP), the amount of storage of the different types required to implement the solution, and the other criteria (e.g., OWN GROUP) and other attributes specified (e.g., PROTECTED). For purposes of illustration, let the criteria OWN GROUP mean that the RAID group from which storage is allocated for the current provisioning request should preferably share storage only with other provisioning requests for the same email application. Data storage system best practices may allocate storage from FAST pool A rather than pool A 2  if available for a candidate solution since RAID-10 may be preferred over the RAID-5 configuration for performance reasons. In this example, processing of candidate solution  204   a  may be performed which determines that there is a sufficient amount of FAST storage pool A storage from which the data volumes for 3 SGs may be allocated, a sufficient amount of FAST storage pool A 2  from which the data volumes for 2SGs may be allocated, and a sufficient amount of CHEAP storage pool B from which all log volumes for the 5 SGs may be allocated. Application best practices may be defined so that storage allocated for each SG may be from a different storage pool however all data volumes for a single SG must belong to the same storage pool and all log volumes for a single SG must belong to the same storage pool. For example, each SG has 2 data volumes and 1 log volume, and storage for both the 2 data volumes may be allocated from either pool A or A 2 . As a result, the foregoing represents a possible way in which the solution  204   a  may be implemented given the available data storage system resources and candidate solution  204   a  storage requirements. 
     In this example, processing of candidate solution  204   b  may be performed which determines that there is an insufficient amount of FAST storage pool A storage for storing the data volumes of the single large SG. However, there is a sufficient amount of FAST storage pool A 2  from which storage may be allocated for the 10 data volumes of SIZE1, and a sufficient amount of CHEAP storage in pool B from which to allocate storage for the 5 log volumes of SIZE2. As a result, the foregoing represents a possible way in which the solution  204   b  may be implemented given the available data storage system resources and candidate solution  204   b  storage requirements. Although both solutions  204   a  and  204   b  may be implemented given the currently available resources of the data storage system, solution  204   a  may be preferred over  204   b  since  204   a  is able to utilize at least a portion of the storage from FAST storage pool A. An embodiment may associate a level of fitness with each candidate solution. The level of fitness may be represented as a metric determined using any one or more different heuristics that may be used in an embodiment to rank the candidate solutions. A candidate solution which cannot be implemented in accordance with currently available resources may have an associated metric value of “0”. In this example, candidate solution  204   a  may be ranked higher than solution  204   b . A list of one or more candidate solutions which can be implemented in accordance with the currently available data storage system resources may be generated. The list may present to the user one or more solutions from which a user may select a solution for implementation to service the current provisioning request. 
     It should be noted that the metric indicating the level of fitness associated with each candidate solution may also be presented to the user. In one embodiment, whether the metric is presented or not may depend on the user proficiency level. For example, the metric may not be presented to NOVICE proficiency level users but may be presented along with the possible solutions to the INTERMEDIATE proficiency level user. Additionally, for NOVICE users, an embodiment may perform processing to automatically service the provisioning request with the highest ranked solution set without further interaction with the user. In other words, the NOVICE user may not be presented with a list of candidate solutions  204   a  and  204   b  or the associated metric. The INTERMEDIATE user may be presented with a ranked list of candidate solutions and the metric indicating a level of fitness for each solution that can be implemented in accordance with data system resources available. In response, the INTERMEDIATE user may select a solution for implementation. 
     As a variation to the foregoing, it may be that there is an insufficient amount of FAST storage in pools A and A 2  to implement either candidate solution  204   a  or  204   b . Furthermore, in connection with solution  204   a , there may be an insufficient amount of storage in pool A and pool A 2  to allocate storage for two data volumes for even a single storage group. However, there may be a sufficient amount of CHEAP storage in pool B for allocating all data volumes and all log volumes for solutions  204   a  and  204   b . As a result, an embodiment may also consider variations of the solutions  204   a  and  204   b  in which all the data volumes and log volumes may be located in the CHEAP storage pool B. The metrics indicating the level of fitness associated with each the foregoing solutions  204   a  and  204   b  when allocating all storage from the CHEAP storage pool B may be less than metric values associated with the foregoing solutions  204   a  and  204   b  when allocating data volumes from the FAST storage pools. 
     As alternative to allocating all storage from the CHEAP storage pool for the NOVICE user, the data storage system may fail to provision storage for the request and output a message that additional FAST storage is needed. The message may recommend adding a number of devices, such as pairs of devices to implement the provisioning request using the preferred RAID 10 implementation in accordance with data storage system best practices. For the INTERMEDIATE user, the user may be presented with the solution sets allocating all storage from the CHEAP storage pool along with a message indicating that there are currently insufficient data storage system resources to satisfy the request in accordance with the recommended types and amounts of FAST and CHEAP storage but that the provisioning request may be satisfied by allocating all from CHEAP storage. The data storage system may also indicate possible penalties or drawbacks in connection with electing to allocate all from CHEAP storage (e.g., performance penalties when accessing email). The INTERMEDIATE user may be given the option of proceeding with the provisioning request by allocating all data and log volumes from CHEAP storage. 
     As described above, it may not be possible to implement a provisioning request due to insufficient available resources on the data storage system. In such instances, processing may be performed to indicate an error or status and recommend installation of additional storage devices in the data storage system in accordance with best practices. Some of these have been outlined above for the particular example. However, an embodiment may perform other alternatives and processing. 
     Referring to  FIG. 5 , shown is an example illustrating use of the techniques herein with the two stage mapping processing as described in connection with  FIG. 1 . The example  300  illustrates use of application provision requirements for the same email application and same number of mailboxes as in connection with the example  200  of  FIG. 4  with the difference that the example  300  illustrates application provision requirements specified for an INTERMEDIATE rather than a NOVICE user proficiency level. The example  300  includes application provision requirements  302  which are input in connection with an INTERMEDIATE user proficiency level for the email application hosting storage on the data storage system. In this example, the requirements of  302  include a server name, such as “SERVER1”, and a number of “power” user mailboxes, such as  300 , and a number of “light” user mailboxes, such as  200 . A “power” user may be characterized as one who uses email frequently (e.g., throughout each day) and tends to store a lot of email data. In contrast, a “light” user may be characterized as one who is not expected to store as much data as a power user and may use email on an infrequent basis (e.g., may not even log on every day and does not receive many emails). A user may characterized as light or a power user in accordance with job tasks. As such, power user mailboxes may be allocated more storage for email data than light user mailboxes. Additionally, power users may have a greater performance demand so that power user mailbox data may be stored on a faster device than that of light users and may also be serviced by a processor A having lighter processing load than another processor B. Both processors A and B may be included in a data storage system having a multiprocessor architecture. 
     In accordance with application best policies, the requirements  302  may be mapped into generic storage requirements  304  resulting in 2 possible candidate solutions  304   a  and  304   b . In this example, the element  304  includes the generic storage resource requirements further annotated with application specific information as will be described in more detail below. Solution  304   a  specifies 5 SGs with 3 SGs for the power users and 2 SGs for the light users. Each of the 3 SGs for the power users may have 2 FAST data volumes each of SIZE3 and 1 CHEAP log volume of SIZE4. Additionally, the power user SGs include CRITERIA=OWN GROUP which means that the data volumes for the SG cannot be included in a RAID group which shares storage with another application other than the email application. Each of the 2 SGs for the light users may have 1 FAST data volume of SIZE3 and 1 CHEAP log volume of SIZE4. Additionally, the light user SG does not indicate CRITERIA=OWN GROUP. Thus, data volumes holding data for the light user mailboxes may be included in a RAID group which shares storage with another application other than the email application. Solution  304   b  includes one large SG with all data volumes allocated from FAST storage and all log volumes allocated from CHEAP storage. The CRITERIA=OWN GROUP on solution  304   b  is as described above in that data volumes may be included in a RAID group having storage allocated for use only with the email application. 
     As described above, the first mapping or translation stage  120  may output generic storage resource requirements and also application-specific information as included in  304   a  and  304   b . With reference to  304   a , the generic resource requirements may include the following information describing generic storage allocated for each of 3 storage groups (SGs) for “Power” users:
         2 Volumes FAST SIZE3, 1 volume CHEAP SIZE4, PROTECTED, CRITERIA=OWN GROUP
 
and generic storage allocated for each of 2 SGs for “Light” users:
       

     1 volume FAST SIZE3, 1 volume CHEAP SIZE4, PROTECTED 
     The remaining information of element  304   a  may be application specific information. For example, application specific information of  304   a  may include information regarding the fact that 5 SGs in total are formed including 3 SGs for Power users and 2 SGs for Light users, each of the 3 Power user SGs contains 100 Mboxes (mailboxes). Each of the 3 Power user SGs consists of a particular number and type of generic storage volumes (e.g., 2 FAST volumes and 1 CHEAP volume). Each of the 2 Light user SGs consists of a particular number and type of generic storage volumes (e.g., 1 FAST volume and 1 CHEAP volume). In other words, the attributes of SG, “Power user”, and “Light user” may be associated with particular instances of provisioned generic storage. Furthermore, as described in connection with  FIG. 4 , the application specific attributes of “Data” and “Log” may be associated with particular generic storage volumes. The attributes of Data, Log, SG, Power user and Light user, may be particular to the email application and used to annotate or further describe information maintained in a data model for other uses such as presenting information on provisioned storage to a user. 
     With reference to  304   b , the generic resource requirements may include the following information describing generic storage allocated for each 1 large SG: 
     8 volumes FAST SIZE3, 5 volumes CHEAP SIZE4, PROTECTED, CRITERIA=OWN GROUP 
     The application-specific information of  304   b  may include the fact that there is a single SG formed and associated with the foregoing generic storage volumes. Furthermore, the application-specific information in  304   b  may include use of the application specific attributes of Data and Log wherein the “Data” attribute is associated with each of the 8 FAST generic storage volumes and the “Log” attribute is associated with each of the 5 CHEAP generic storage volumes. 
     Element  310  indicates the currently available storage in each of the storage pools and is analogous to the information of element  210  of  FIG. 4 . In connection with solutions  304   a  and  304   b , there may be a sufficient amount of data storage using FAST pool A and CHEAP pool B to implement both solutions  304   a  and  304   b . Solution  304   a  may be preferred due to application best practices of provisioning resources where possible in accordance with the specified types of power and light email users. As such, solution  304   a  may receive a higher level of fitness ranking than solution  304   b . For the INTERMEDIATE user, a list of solutions  304   a  and  304  along with a ranking in accordance with level of fitness may be presented. The user may then select one of the solutions for implementation. 
     Referring to  FIGS. 6 and 7 , shown are flowcharts of processing steps that may be performed in an embodiment in connection with the techniques herein for processing a provisioning request for data storage. The processing steps summarize processing as described above. At step  502 , the user inputs for the provisioning request are received. Step  502  includes receiving the application provision requirements  102  of  FIG. 2  that may vary with application and user proficiency level. At step  504 , the user inputs are analyzed in accordance with the application best practices to determine the generic resource requirements. Step  504  includes performing the first mapping or translation stage  120  of  FIG. 2 . At step  504 , a list of one or more candidate solutions may be determined. The list of candidate solutions may include different ways in which the generic resource requirements may be expressed, for example, as illustrated by elements  204   a  and  204   b  of  FIG. 4  and elements  304   a  and  304   b  of  FIG. 5 . Step  508  analyzes the current data storage system configuration of available storage in accordance with each possible solution of the candidate list to determine which of the candidate solutions can possibly be implemented in accordance with the currently available resources of the data storage system. Additionally as part of step  508 , a fitness level or metric may be associated with each candidate solution so that the solutions can be ranked. Such a metric may be used in connection with selecting a best solution from multiple candidate solutions. At step  510 , a determination is made as to whether implementation of any candidate solution indicated in the candidate list is possible in accordance with the currently available resources of the data storage system. If step  510  evaluates to no, control proceeds to step  512  to perform error processing. As described above, an embodiment may determine that if a candidate solution cannot be implemented in accordance with the specified storage types (e.g., FAST and CHEAP) and amounts of storage required with the particular characteristics (e.g., PROTECTED attribute and OTHER CRITERIA that may be specified), step  510  may evaluate to NO. As a variation, an embodiment may consider alternatives or acceptable variations to candidate solutions. For example, a candidate solution may specify a first amount of FAST storage and a second amount of CHEAP storage. There may be insufficient resources to obtain the first amount of FAST storage. However, if no other solutions are possible, an embodiment may consider implementing the provisioning request using all CHEAP storage. Whether such a variation is considered and acceptable may vary with an embodiment. 
     If step  510  evaluates to yes, control proceeds to step  514  where a determination is made as to whether automated processing is performed in connection with implementation of the provisioning request. As described herein, an embodiment may perform such automated processing in accordance with the currently specified user proficiency level, configuration settings or options, and the like. For NOVICE users, the best candidate solution may be selected and automatically implemented without further user interaction. If step  514  evaluates to yes, control proceeds to step  516  to automatically implement the provisioning request in accordance with the best candidate solution from step  508 . As described herein, the best solution may be determined in accordance with a fitness level expressed as a metric. If step  514  evaluates to no, control proceeds to step  518  to present the one or more possible candidate solutions which can be implemented to the user. At step  520 , processing waits for a user selection. In one embodiment, a user may be presented with the list of candidate solutions which can be implemented and also an option to abort the provisioning request so that no solution is selected. Once a user inputs a selection, control proceeds to step  522 . At step  522 , a determination is made as to whether there has been a selection to abort the provisioning request. If so, control proceeds to step  524  where no processing is performed to implement the request. If step  522  evaluates to no, control proceeds to step  526  to implement the provisioning request in accordance with the solution selected. Step  526  may include allocating storage from the appropriate storage pools. As will also be described in more detail in following paragraphs, step  526  may include performing other processing including configuring physical devices or RAID groups into storage pools depending on the data storage system policy and state of the data storage system. 
     As described above, data storage configuration processing in connection with configuring physical data storage devices into storage pools for use with the techniques herein may be performed at various times in the lifecycle of a data storage system. Additionally different degrees or levels of physical data storage device configuration may be performed at different times. To further illustrate, reference is made to  FIG. 3 . Data storage devices may be configured for use with the techniques herein to form storage pools. Thus, prior to data storage of a physical device of  152   a - 152   b  being allocated for use in connection with servicing a provisioning request, the physical device may be associated with a storage pool in accordance with data storage system best practices. There are different points in time at which the physical devices may be configured for use in storage pools. As described above, physical devices may be partitioned and configured into storage pools as part of data storage system initialization or startup. At such a time, the physical devices currently present in the data storage system may be configured into one or more storage pools. As a variation, an embodiment may not configure all physical data storage devices into storage pools as part of startup or initialization processing. Rather, an embodiment may configure a certain amount of storage capacity, number of physical devices, and the like, into storage pools in accordance with a defined policy so that a portion of the physical devices are not associated with a storage pool after data storage initialization processing is complete. As a result, a portion of the physical devices may be configured dynamically or as part of processing a received provisioning request. Such processing may be performed, for example, as part of step  526  processing of  FIG. 7  and may allow for configuring the physical devices in accordance with the current provision request. In other words, rather than decide at data storage system initialization time how to configure all available physical devices, a portion of the physical devices may remain unassociated with storage pools so that the portion of physical devices may be so configured in accordance with provision requests actually received. An embodiment may not know at data storage system initialization time how best to configure all the physical devices into storage pools since it may not be known at that time how such data storage may actually be consumed by one or more applications. Binding of a physical device to a storage pool as well as defining which particular data storage processor in a multiple processor data storage system architecture may not be modifiable once specified. As such, an embodiment may choose to form the storage pools and also associate other non-modifiable attributes with data storage at a later point in time. 
     It should also be noted that an embodiment may elect to partially configure a portion of physical devices in accordance with a data storage system policy. With reference to  FIG. 3  beginning at the bottom point or leve, a data storage configuration may include forming RAID groups  154   a ,  154   b  from physical devices  152   a ,  152   b , forming data LUNs  156   a ,  156   b  from RAID groups  154   a ,  154   b , and forming device volumes  158   a ,  158   b  (and other entities associated with the other logical device layers) from LUNs  156   a ,  156   b . As such, physical devices may also be partially configured for use with storage pools by performing configuration processing to one of the foregoing configuration processing points or levels. For example, at data storage system initialization time, a first portion of the physical devices may be configured into storage pools. The remaining portion of physical devices may be configured into RAID groups. However, additional processing to form data LUNs and device volumes from the RAID groups may not be performed until a later point in time such as in connection with processing a provisioning request. Data storage may be first allocated from formed storage pools with the remaining portion of physical devices being configured into the appropriate storage groups as needed in accordance with subsequently received provisioning requests. For example, as storage from a first storage pool is allocated for use with provisioning requests, additional RAID groups may be added to the first storage pool. In one embodiment having a multiprocessor data storage architecture, when RAID groups are configured into data storage LUNs, a data storage processor may be assigned to service I/O requests for the LUNs. An embodiment may choose to determine which data storage processor services a LUN (e.g., perform the processor-LUN assignment or binding) at a later point in time after the RAID groups are configured in accordance with current load or tasks being performed by each data storage processor. For example, as described elsewhere herein in more detail, the RAID group configuration may be performed as part of initializing the data storage system or when a new device is detected. Performing the processor-LUN assignment, along with other configuration beyond the RAID group formation, may be performed at one or more later points in time, for example, after one or more provisioning requests have been processed. 
     Thus, based on the foregoing, data storage device configuration, such as performed at data storage system initialization, may be performed in varying degrees or amounts specified in accordance with several aspects. In accordance with a first aspect, a certain amount of the physical devices may be configured into storage pools. The amount may be determined based on a number of physical devices and associated characteristics such as capacity. The amount may be determined based on forming one or more storage pools to have a threshold amount of configured data storage of one or more types (e.g., a first threshold amount of FAST storage, a second threshold amount of CHEAP storage, a number of storage pools of each type FAST and CHEAP, and the like). In accordance with a second aspect, the physical devices may be configured to varying degrees or levels. For example, as part of data storage initialization processing, a first portion of physical devices may be configured into storage pools ready for use in connection with allocation for generic requirements. A second portion of physical devices may only be configured to the RAID group level so that they may be configured at a later point in time into appropriate storage pools, assigned for servicing by a data storage processor, and the like, in accordance with subsequently received provision requests and data storage system state. As an example, the data storage processor which is assigned to service LUN I/O requests may vary in accordance with which processor is more heavily loaded to provide for load balancing. Also, LUNs of FAST storage pools may be assigned to the least or lesser loaded processors. 
     Storage devices may also be added to the data storage system as additional storage capacity is needed. As such, the subsequently added devices may be configured when added to the data storage system as well as at some point in time after being added but prior to allocating the storage thereof in connection with a provisioning request. In a manner similar to as described above, newly added devices may be completely configured into storage groups when added, or may be partially configured. The newly added devices may be partially configured in accordance with a first aspect as described above by only configuring a portion of physical devices into storage pools. In accordance with another aspect, a newly added device may be partially configured in that a physical device may be configured to the RAID group or other configuration level so that the physical device-storage pool binding is not complete. It should be noted that, with reference to  FIG. 3 , an embodiment may include other levels or stages in connection with configuring physical devices into storage pools for use with the techniques herein. An embodiment may partially configure one or more physical devices by performing configuration processing to a point, such as associated with level or stage  154 ,  156 , and/or  158 . The reasons for performing configuration to a particular level or stage with reference to  FIG. 3  may vary with the particular data storage system best practices and policy. 
     In accordance with the techniques herein, application best practices, and thus the code implementing the same, may change over time. For example, application best practices may be change for a particular application as new features are added, with a software version upgrade, as runtime behavior and application implementation associated with an existing feature changes, as best practices are improved with better ways of implementation, and the like. In connection with a modification to an application best practice, an embodiment implementing such application best practices using a policy may download a new code module, script, and the like, which implements the current application best practices. For example, an updated script or set of rules may be used to define a revised application best practices for an email application. The new script or set of rules may be downloaded to the data storage system, for example, from a vendor or VAR (value added reseller) website or other network location as well as from storage local to the data storage system, such as from a CD, USB or flash memory device, and the like. 
     In accordance with the techniques herein, a data storage vendor may supply an implementation of data storage system best practices in the form of a policy. Another party, such as a VAR, may supply an implementation of application best practices in the form of a policy for VAR-supplied applications. For example, the VAR may have customers which use a VAR supplied application, such as a medical office application, law office application, dental office application, and the like. The application may be customized or particular to a vertical market, profession, service, and the like. The VAR may supply a script or other code module which implements the application best practices for provisioning storage. Additionally, the VAR may also supply a policy and appropriate configuration settings which allows for automation of best practices and specification of a user proficiency level(s) for the different customers. The policy may also indicate an amount of data storage for which configuration into storage pools is performed or a degree to which data storage devices are configured. The foregoing may be used in connection with initialization processing as well as when new devices are added. 
     Referring to  FIG. 8 , shown is a flowchart of processing steps that may be performed in an embodiment in connection with configuring physical storage devices for use with the techniques herein. The flowchart  600  summarizes processing described above as may be performed in an embodiment by code included in a data storage system in connection with configuring physical data storage system devices and resources in accordance with data storage system best practices. The data storage system best practices may be applied at a different point in time independent of when the application best practices are applied. In other words, with reference to  FIG. 2 , the second mapping or translation process  122  may be applied in flowchart  600  processing (e.g., steps  610  and  612 ) to configure physical data storage system devices for use with the techniques herein. At step  602 , a determination is made by the data storage system as to whether the data storage system is being initialized, for example, as part of starting up the data storage system. Step  602  may evaluate to yes, for example, the first time the data storage system is powered on and the processing steps of  600  may be performed as part of data storage system initialization processing. If step  602  evaluates to yes, control proceeds to step  606  where a determination is made as to whether automated data storage configuration is to be performed. As described herein, a data storage system may have settings or options indicating whether data storage configuration as part of initialization should be performed automatically without user interaction. As an example, automated configuration may be performed if the user proficiency level is indicated as NOVICE. Such an indication may be made via a setting or option by a VAR providing the data storage system to a customer, through a user selected proficiency or interaction level, and the like. If step  606  evaluates to yes, control proceeds to step  612  to automatically configure the physical storage devices in accordance with a default policy. As described herein, a policy may be specified which defines how to form one or more different types of storage pools from physical devices as illustrated in  FIG. 3  in accordance with data storage system best practices. For example, a policy may specify how to configure CHEAP and FAST storage pools from physical devices as part of step  612  processing. The policy may also indicate a number or percentage of each of the different types of storage pools which are to be configured from the physical devices. For example, a policy may indicate that 50% of the physical devices are to be configured as FAST storage pools and the remaining 50% are to be configured as CHEAP storage pools. As another example, the policy may indicate that not all of the physical storage devices are to be configured into storage pools. Rather, the policy may indicate that only a portion of the physical devices are to be configured into storage pools as part of step  612  processing with the remaining physical devices being left unconfigured until a later point in time, or configured up to the RAID group level (with reference to  FIG. 3 ). At various later points in time in accordance with the policy, the remaining physical storage devices (or portion thereof) may be configured as part of a storage pool, for example, as additional storage for an existing pool is needed when processing a received provisioning request. 
     If step  606  evaluates to no, control proceeds to step  608  to initiate a user dialogue. The language of the dialogue, types of questions asked and information presented may vary with a selected or set user proficiency level. The dialogue may proceed to ask the user a series of questions and obtain information used in connection with configuring the physical storage devices. For example, the user dialogue may inquire whether to use the policy defaults regarding portion of storage to be configured into storage pools, percentage of each type of storage pool (e.g, 50% FAST and 50% CHEAP) at data storage system initialization. The user, such as one having an EXPERT user proficiency level, may elect to modify the percentages or amounts directly. As an alternative (e.g., such as with an INTERMEDIATE user level), the dialogue may ask the user a series of questions regarding intended use of the storage such as what particular applications are going to host data on the data storage system, expected usage information for each application, and the like. Such information may be used in connection with determining how to configure the physical storage. For example, if the data storage system will be hosting data only for an email application, a particular database application, and the like, the percentages of the different storage pools types (e.g., FAST and CHEAP) may be adjusted accordingly (e.g., to ratios other than 50% CHEAP and 50% FAST). If the user responds that intended usage is unknown, only a portion of the physical storage devices may be configured into storage pools as part of the initialization processing leaving the remaining physical storage devices for configuration at a later point in time. At step  610 , the physical devices of the data storage system are configured in accordance with the responses received in step  608 . 
     If step  602  evaluates to no, control proceeds to step  604  where a determination is made as to whether new devices have been added to the data storage system. If so, step  604  evaluates to yes and control proceeds to step  616  to perform new device processing to configure the new storage devices for use with the techniques herein. Additional detail regarding step  616  that may be performed in an embodiment is set forth in connection with  FIG. 9  described below. If step  604  evaluates to no, control proceeds to step  614  to continue with other processing. 
     Referring to  FIG. 9 , shown is a flowchart of processing steps that may be performed in an embodiment in connection with configuring a new storage device. The flowchart  650  sets forth additional processing steps that may be performed in an embodiment in connection with step  616  of  FIG. 8 . Steps  652 ,  654 ,  656 , and  658  are respectively analogous to steps  606 ,  612 ,  608  and  610  of  FIG. 8  with the difference that the processing steps of  FIG. 9  are performed with respect to additional storage devices that may be added to a data storage system at a point in time after data storage system initialization. The new storage devices may be added, for example, to expand the storage capacity of an existing data storage system. Processing steps  654  and  658  of  FIG. 9  may utilize defined data storage system best practices (e.g., how to configure CHEAP and FAST storage pools for the particular data storage system). 
     It should be noted that the different ways and variations in which physical devices of the data storage system may be configured, or partially configured, also apply to newly added physical devices. 
     It should be noted that an embodiment may perform new device processing of  FIG. 9  when the addition of new storage devices is detected by the data storage system. Such detection may be performed in an automated fashion by the data storage system. The policy may also specify default values for use in connection with added devices which differ from those values and settings that may be specified for use in connection with initially configuring the devices of the data storage system, such as when the data storage system is first powered on. For example, a policy may indicate that automated configuration of data storage devices is performed at data storage system initialization (e.g., step  606  of  FIG. 8  evaluates to yes). However, such automated configuration may not be performed by default for subsequently added devices (e.g., step  656  of  FIG. 9  evaluates to no). The user dialogue at step  656  may be initiated when a new device is detected. When a user logs into the data storage system, a visual indicator or message may be presented to the user on a UI indicating that the newly added device needs to be configured. Upon selection of the visual indicator by the user, the dialogue for configuring the newly added devices may be commenced. The user dialogue that may be performed in an embodiment at step  656  may ask questions to determine if storage of the newly added devices should be configured to increase storage of existing storage pools, or to create a new storage pool for use by a new application not currently hosting data on the data storage system. As in connection with the user dialogue of step  608  of  FIG. 8 , the user dialogue at step  656  may be customized for a particular user proficiency level. 
     The data storage system best practices may provide a recommendation in connection with newly added devices prior to configuring the new devices. For example, in accordance with a data storage system best practice, a policy may be defined in which a RAID-5 (4+1) configuration may be specified for FAST RAID group configurations. The data storage system may detect the addition of 4 new devices and the user may indicate that he/she wishes to configure storage of the new devices for use as an additional FAST storage RAID group for a new FAST storage pool. Thus, 5 devices may be needed to configure a new FAST RAID group. The data storage system may output a message that the newly added 4 devices cannot be configured for use as a new FAST RAID group unless an additional 5 th  device is added. As an alternative, the data storage system may indicate other ways in which the 4 new physical devices may be configured. 
     In accordance with techniques and the examples herein, a policy may implement data storage system best practices to define how to form different types of storage pools. For example, a policy may specify how to form FAST and CHEAP storage pools described herein. Several different device and configuration characteristics may be used to configure a type of storage pool. For example, one or more of the following may be used in specifying the data storage system best practices in a policy: RAID-level, number of data and/or disks, drive hardware characteristics (e.g., Fibre channel or ATA drive), whether data is striped, which data storage processor is used to service I/O requests (e.g., may be considered in a multiprocessor data storage system architecture; the selected process may vary with the load on a given processor and desired performance for a storage pool). 
     It should be noted that a choice of RAID type and configuration may impact the performance of read and write operations. For example, a RAID-5 configuration which uses 4 data drives and 1 parity drive may provide faster write performance than a RAID-5 configuration which uses 8 data drives and 1 parity drive. As such, an embodiment may use RAID-5 (4+1) configuration with FAST storage pools and a RAID-5 (8+1) configuration with CHEAP storage pools. The foregoing data storage system best practices defining CHEAP and FAST may vary with data storage system and associated devices types. 
     Referring to  FIGS. 10 and 11 , shown are examples representing information that may be included in a policy in an embodiment. The particular way in which the information is encoded may vary with implementation. With reference to  FIG. 10 , elements  702   a  and  702   b  may specify options for use in connection with configuration of data storage devices at different points in time during the life cycle of the data storage system. Element  702   a  includes options used in connection with data storage initialization processing, for example, when the data storage system is first powered on. Element  702   a  indicates that the data storage configuration at initialization time is performed in an automated fashion (e.g., AUTOMATED option) with 40% of the physical storage capacity configured as CHEAP storage pools and 40% of the physical storage capacity configured as FAST storage pools (e.g., CONFIGURE=40% CHEAP, 40% FAST). With reference to  FIG. 3 , the remaining physical storage capacity is configured up to the RAID group level (e.g., CONFIGURE=REMAINING, RG) and not yet configured into LUNs, storage pools, and the like. Element  702   b  indicates that the data storage configuration performed when a new device is subsequently added is performed with a user dialogue associated with an EXPERT proficiency level. A default or starting point for new device configuration is specified (e.g., DEFAULT=50% CHEAP, 50% FAST, NEW STORAGE POOLS) where new storage pools may be formed from the newly added storage with 50% forming a new CHEAP storage pool and the remaining 50% forming a new FAST storage pool. The user dialogue in this example may relay the foregoing default configuration to the user and provide the user with an opportunity to modify the percentages or accept the defaults. 
     Elements  704   a  and  704   c  may specify the data storage system best practices included in a policy for a first data storage system type DS 1 . Element  704   a  specifies how to configure CHEAP storage pools for data storage system DS 1  using a RAID-5 (8+1) configuration with 8 data drives and 1 parity drive with ATA data storage drives. Element  704   c  specifies how to configure FAST storage pools for data storage system DS 1  using a RAID-5 configuration with 4 data drives and 1 parity drive with Fibre Channel storage drives. Elements  704   b  and  704   d  may specify the data storage system best practices included in a policy for a second data storage system type DS 2 . Element  704   b  specifies how to configure CHEAP storage pools for data storage system DS 2  using a RAID 5(8+1) configuration with ATA data storage drives. Element  704   d  specifies how to configure FAST storage pools for data storage system DS 2  using a RAID-6 (3+2) configuration on Fibre Channel drives. 
     With reference to  FIG. 11 , shown are example representations of application best practices for an email application and a dental office application. Elements  752   a  may indicate defaults used in connection with determining generic storage requirements for a single storage group when a user requests creation of between 1-100 mailboxes. Element  752   a  may be used in connection with a NOVICE user specifying a number of mailboxes for which a provisioning request is made as described, for example, with reference to  FIG. 4 . Elements  752   b  and  752   c  may be used in connection with determining generic storage requirements for application requirements input from an INTERMEDIATE user issuing a provisioning request as described, for example, with reference to  FIG. 5 . Element  754   a  may be used in connection with provisioning storage for a dental office action for a NOVICE user specifying a number of records (NUM_RECORDS  756 ). Element  754   a  determines an allocation size or amount of storage as NUM_RECORDS*100 on FAST storage and an amount (LOGSIZE) of CHEAP storage for logging data transactions with the dental office application. The CRITERIA indicates that the storage pools used for the provisioning request should be EXPANDABLE and have sufficient storage available for subsequent provisioning requests. The CRITERIA of OWN RG indicates that the storage provisioned for the dental office application is to be included in a RAID group which is not shared with another application. 
     Using the techniques herein, the best practices for applications and data storage systems may be codified in any one of a variety of different forms and may be supplied independently of the underlying software installed on the data storage system. A vendor, VAR or other third party may customize scripts or other forms used to implement the application and/or data storage system best practices. The forgoing scripts or other implementation of the best practices may be provided to a customer in a variety of different ways as described herein. A VAR or other party may also customize a codified version of the application or data storage system best practices as well as set other configuration options and defaults for use with the techniques herein by a particular customer. The foregoing may be customized for use by a customer having a particular proficiency level, such as NOVICE, in which the techniques herein may be performed in an automated fashion. 
     Described herein are techniques for performing resource provisioning based on application best practices automated at varying degrees in accordance with a user proficiency level. The techniques herein may be used to automatically configure and provision storage pools from which generic storage objects, such as volumes, may be created for use in connection with allocating storage for an application. Storage pools may be created, modified and managed in an automated fashion based on best practices for the particular data storage system. Storage pool configuration and provisioning may be performed in a separate stage from the provisioning of resources in connection with an application provisioning request which uses the application best practices. Storage pool configuration and provisioning, such as illustrated in  FIG. 3 , may also take into account application best practices, for example, by determining how much of particular storage pool types (e.g., FAST and CHEAP) to configure based on what application may use the storage. Storage pools may be configured or formed from physical devices at various points in time during the life cycle of the data storage system and to varying degrees. Physical devices may be configured, completely or partially, for use in storage pools at data storage system initialization, when new storage devices are added, and/or as part of processing in connection with a provisioning request. As described herein, a policy may be a formal description or implementation of best practices. The policy may be applicable for use with different application input requirements that may vary with user level of proficiency. New or updated policies may be provided for use on the data storage system independent of other data storage system software upgrades. Different aspects of the techniques herein, such as user dialogues and varying the degree to which storage provisioning and configuration may be automated, may be in accordance with user proficiency levels. 
     As will be appreciated by those skilled in the art, the examples described herein may be simplistic for purposes of illustration of the techniques herein. An embodiment may have a greater amount of detail and complexity in order to provide automation of the best practices. 
     The foregoing provides a flexible approach for automated implementation of best practices that can be customized in accordance with the particular application, data service, and/or data storage system. The best practices may vary with application as well as the particular data storage system. The foregoing describes techniques that may be used to map provision requirements from an application domain to requirements in the storage domain in connection with a two stage mapping or translation process. The input provision requirements in the application domain may be applied and vary with different user proficiency levels. A user may select a level of interaction with the system in which the level selected varies the assumed knowledge or user sophistication, level of detail, and level of automation for the particular application. The user may select a level, such as NOVICE level, to obtain a greater level of automation of best practices customized for the particular application. A user may also select to obtain a lesser level of automation of best practices as the user knowledge level and sophistication increases. The proficiency levels may relate to the different knowledge levels associated with performing data storage management tasks such as provisioning and data storage configuration. The selected level may be associated with a particular user interface, level of automation and interaction with the data storage system for performing data services for a particular application. The automation of the best practices may be implemented using a variety of different frameworks and infrastructures. The ones mentioned herein, such as use of scripts or a rule-based system, are exemplary and it will be appreciated by those skilled in the art that others are possible to implement the techniques set forth herein. 
     The data storage system may automatically detect that new or updated policies are available. For example, the data storage system may be able to communicate with a network location such as an external website of a vendor and/or VAR website. The data storage system may detect new or updated policies using any one of a variety of different techniques including polling the one or more websites for changes or by having the one or more websites send a notification to the data storage system when new or updated policies are available. When a user logs into the data storage system, the UI may then display an indicator regarding the availability of the new or updated policies. The user may then initiate processing to obtain the new or updated policy in which the data storage system communicates with the external website or other network location. Depending on data storage configuration options, settings, and the like, the foregoing process may be performed automatically without any user interactions as updated or new policies are published. The new or updated policies may also be uploaded from a local storage device on the data storage system. For example, a user may insert a CD, USB device, and the like, containing the updated or new policies. The data storage system may then upload the foregoing policies for use by the data storage system. 
     In connection with the techniques herein regarding best practices for applications, exemplary applications such as a database application or an email application are illustrated herein although the techniques herein regarding application best practices may be applied with any application. Other applications may include, for example, a web server such as the Apache Web Server (also referred to as the Apache HTTP Server), different business applications such as a spreadsheet, presentation software (e.g., Microsoft® Office PowerPoint®), and word processing software, and different types of virtualization software, such as the VMware ESX Server provided by VMware, Inc. Virtualization software may allow a computer to run multiple operating systems on a single computer system. 
     An embodiment may implement the techniques herein using code executed by a computer processor. For example, an embodiment may implement the techniques herein using the rules, rules engines, and the like, using code which is executed by a processor of the data storage system. As will be appreciated by those skilled in the art, the code may be stored on the data storage system on any one of a computer-readable medium having any one of a variety of different forms including volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by a data storage system processor. 
     While the invention has been disclosed in connection with preferred embodiments shown and described in detail, their modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention should be limited only by the following claims.