Abstract:
A system manages a file directory containing data that is exposed by a file-server. The system provides a block-device layered on top of a network share that treats the underlying network share as read-only but allows local file-system semantics to operate on top of the network share. The end-result is a virtual disk containing a locally recognizable file-system that can read and write from the perspective of the operating system but where the data is store in the cloud as network shares. The virtual disk appears to be a fully functional local disk with all the expected local disk semantics.

Description:
CROSS REFERENCE TO RELATED DOCUMENTS 
       [0001]    The application is a Continuation In Part (CIP) application of and claims priority to U.S. patent application Ser. No. 13/104,179, filed May 10, 2011, entitled “BACKUP MEDIA CONVERSION VIA INTELLIGENT VIRTUAL APPLIANCE ADAPTER,” which is a CIP of and claims priority to U.S. patent application Ser. No. 12/766,778 (now U.S. Pat. No. 9,087,066), filed Apr. 23, 2010, entitled “VIRTUAL DISK FROM NETWORK SHARES AND FILE SERVERS,” which claims priority to U.S. Provisional Patent Application No. 61/172,218, filed Apr. 24, 2009, entitled “VIRTUAL DISKS AND BOOTABLE VIRTUAL DISKS FROM NETWORK SHARES AND FILE SERVERS,” U.S. Provisional Patent Application No. 61/176,098, filed May 6, 2009, entitled “CLOUDSAFE—MULTI-FUNCTION CLOUD STORAGE AND ON-DEMAND WORKPLACE GATEWAY,” and U.S. Provisional Patent Application No. 61/218,419, filed Jun. 19, 2009, entitled “BACKUP MEDIA CONVERSION VIA INTELLIGENT VIRTUAL APPLIANCE ADAPTER.” All of the above patents and applications are incorporated by reference herein for all that the patents and applications teach and for all purposes. 
     
    
     BACKGROUND 
       [0002]    Storage of enterprise data has moved from local storage to networked storage in the cloud. The days of built infrastructure tied to corporate premises are a thing of the past. Businesses are demanding ready-made Information Technology (IT) that service business quickly and seamlessly. However, businesses need the cloud data to be protected and managed. Indeed, some industry segments require data retention for regulatory reasons, and other businesses need to make corporate applications instantly available to remote locations with access to the cloud-stored data. These demands can overwhelm a business&#39; existing IT staff. 
       SUMMARY 
       [0003]    It is with respect to the above issues and other problems that the embodiments presented herein were contemplated. Embodiments of systems and methods described herein provide disk virtualization where network share data can be stored to cloud storage. A disk virtualization system creates a virtual disk. The virtual disk can appear as a representation of a local disk. The virtual disk has associated metadata that is exposed to the local file system of the computer system. The metadata allows the file data to be stored to the cloud in blocks that may be retrieved later either from the same network or another network or remote location. Each file stored in the network share needs metadata that wraps the file. The metadata wrapper provides the necessary information for the file system to have files exposed via the network share appear as locally-stored files with requisite on-disk structures. 
         [0004]    Given a directory containing useful data that is exposed by a file-server either via NFS, CIFS or other file oriented protocol, create a block-device layered on top of the network share that treats the underlying share as read-only but allows local file-system semantics to operate on top. The end-result is a disk containing a locally recognizable file-system like NTFS, or EXT3, etc. (depending on what the operating system is capable of understanding) that is read-write from the perspective of the OS and is a fully functional local disk with all the expected local disk semantics. 
         [0005]    The phrases “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together. 
         [0006]    The term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. It is also to be noted that the terms “comprising”, “including”, and “having” can be used interchangeably. 
         [0007]    The term “automatic” and variations thereof, as used herein, refers to any process or operation done without material human input when the process or operation is performed. However, a process or operation can be automatic, even though performance of the process or operation uses material or immaterial human input, if the input is received before performance of the process or operation. Human input is deemed to be material if such input influences how the process or operation will be performed. Human input that consents to the performance of the process or operation is not deemed to be “material”. 
         [0008]    The term “computer-readable medium” as used herein refers to any tangible storage that participates in providing instructions to a processor for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media includes, for example, NVRAM, or magnetic or optical disks. Volatile media includes dynamic memory, such as main memory. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, magneto-optical medium, a CD-ROM, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, a solid state medium like a memory card, any other memory chip or cartridge, or any other medium from which a computer can read. When the computer-readable media is configured as a database, it is to be understood that the database may be any type of database, such as relational, hierarchical, object-oriented, and/or the like. Accordingly, the invention is considered to include a tangible storage medium and prior art-recognized equivalents and successor media, in which the software implementations of the present invention are stored. 
         [0009]    The terms “determine”, “calculate”, and “compute,” and variations thereof, as used herein, are used interchangeably and include any type of methodology, process, mathematical operation, or technique. 
         [0010]    The term “module” as used herein refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and software that is capable of performing the functionality associated with that element. Also, while the invention is described in terms of exemplary embodiments, it should be appreciated that individual aspects of the invention can be separately claimed. 
         [0011]    The term “in communication with” as used herein refers to any coupling, connection, or interaction using electrical signals to exchange information or data, using any system, hardware, software, protocol, or format. 
         [0012]    The term “virtual” or “virtualization” as used herein refers to a logical representation of some other component, such as a physical disk drive. In other words, the “virtual” component is not actually the same as the physical component it represents but appears to be the same to other components, hardware, software, etc. of a computer system. 
         [0013]    The term “disk” as used herein refers to a storage disk or other memory that can store data for a computer system. 
         [0014]    The term “cloud” or “cloud computing” as used herein refers to Internet-based computing, whereby shared resources, software, and information are provided to computers and other devices on-demand, like a public utility. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The present disclosure is described in conjunction with the appended figures: 
           [0016]      FIG. 1  is a block diagram of an embodiment of a disk virtualization system operable to create a virtual disk for a computer system that stores data to a cloud storage; 
           [0017]      FIG. 2A  is a block diagram of a server that includes a virtualization module; 
           [0018]      FIG. 2B  is a block diagram of the virtualization module components operable to create a virtual disk; 
           [0019]      FIG. 3A  is a block diagram of embodiments of data structure communications between a user, the virtual disk, and/or the cloud storage; 
           [0020]      FIG. 3B  is another block diagram of embodiments of data structure communications between a user, the virtual disk, and/or the cloud storage; 
           [0021]      FIG. 3C  is a block diagram of embodiments of data structures associated with cloud storage providers; 
           [0022]      FIG. 4  is a flow diagram of an embodiment a process for managing data within cloud storage; 
           [0023]      FIG. 5  is a flow diagram of an embodiment a process for writing data to the cloud; 
           [0024]      FIG. 6  is a flow diagram of an embodiment a process for reading data from the cloud; 
           [0025]      FIG. 7  is a flow diagram of an embodiment a process for purging data from the cloud; 
           [0026]      FIG. 8  is a flow diagram of an embodiment a process for de-duplicating data in the cloud; 
           [0027]      FIG. 9  is a flow diagram of an embodiment a process for resurrecting a alternate personality with data from the cloud; 
           [0028]      FIG. 10  is a block diagram of an embodiment of a computing environment; 
           [0029]      FIG. 11  is a block diagram of an embodiment of a computer system. 
       
    
    
       [0030]    In the appended figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a letter that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label. 
       DETAILED DESCRIPTION 
       [0031]    The ensuing description provides embodiments only, and is not intended to limit the scope, applicability, or configuration of the invention. Rather, the ensuing description will provide those skilled in the art with an enabling description for implementing the embodiments. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the appended claims. 
         [0032]    An embodiment of a disk virtualization system  100  for storing data to cloud storage is shown in  FIG. 1 . A disk virtualization system  100  can create a virtual disk at a server  106  or a user computer  102 . The virtual disk can expose network share data, stored in a cloud  108 , as a local disk at the server  106  or user computer  102 . The disk virtualization system  100  can include one or more components including, but not limited to, a user computer  102 , one or more networks  104   a  and  104   b,  a server  106 , and a cloud  108 . 
         [0033]    Both the user computer  102  and the server  106  are computer systems such as those described in conjunction with  FIGS. 8 and 9 . A user computer  102  can be any end user device, such as, a personal computer, a laptop, a mobile device, or some other computer system. A server  106  can also be a computer system, such as those described in conjunction with  FIGS. 8 and 9 , that stores or shares data with one or more user computers, such as, user computer  102 . The server  106  may include one or more storage arrays or disks locally that store data for one or more users. 
         [0034]    The server  106  can be physical hardware that resides at the perimeter of the enterprise network  104   a  and acts as the gateway from the network  104   a  through network  104   b  to cloud storage  108 . As such, the server  106  can become a backup end-point (target) for the entire enterprise  104   a.  Once inserted into an enterprise environment, the server  106  (also referred to as an appliance) may inter-operate with existing backup practices while providing secure caching and encrypted offline storage. The enterprise can back up to the appliance  106  and treat the appliance  106  as infinite storage. In some configurations, recently backed up data may be stored and made available locally, on the appliance  106 , and can be restored subject to existing enterprise security protocols. 
         [0035]    The user computer  102  can be in communication with the server  106  through a network  104   a  and the server  106  in communication with the cloud  108  through network  104   b.  A network  104  can be a local area network (LAN), a wide area network (WAN), an intranet, a wireless network, the Internet, etc. The network  104  can function to allow communications between one or more computer systems. The network  104  may communicate in any protocol or format understood by any type of computer system, such as, TCP/IP, RTP, etc. Regardless, the network  104  can exchange communications between a user computer  102 , the server  106 , and/or the cloud  108 . 
         [0036]    The cloud  108  represents networked applications and storage that may be executed by one or more systems within a networked environment. The cloud  108  can include one or more servers. In embodiments, the cloud  108  includes a storage system  110 . The storage system  110  can be a storage area network (SAN), a disk array, or some other storage that allows the server  106  to store data in the cloud  108  as network shares. Further, the cloud  108  can represent two or more storage providers, such as AMAZON™, NIRVANIX™, etc. 
         [0037]    An embodiment of the server  106  is shown in  FIG. 2A . The server  106  is shown as having a virtualization module  204  in  FIG. 2A . It should be noted that the user computer  102  and/or a server associated with the cloud storage  108  may also include a virtualization module  204 , as described herein. As such, the description of  FIG. 2A  can apply to the server  106 , the user computer  102 , and/or the cloud  108  shown in  FIG. 1 . Generally, the server  106  can include one or more user applications  202 , the virtualization module  204 , an operating system  206 , and one or more virtual disks  208 . 
         [0038]    The one or more user applications  202  can be any software that provides functionality to a user. The user applications  202  can include services or other functions that provide functionality between the server  106  and the user computer  102  and/or between the server  106  and a device connected to the server  106  from a remote location or virtual connection (e.g., a kiosk computer at an airport). User applications are understood in the art and will not be explained further. 
         [0039]    The operating system  206  can be any operating system for the server  106 , such as, Windows Server or Linux. The operating system  206  controls the execution of processes or user applications  202  and any other functions of the server  106 . Operating systems  206  are also well known in the art and will not be explained further. 
         [0040]    A virtualization module  204  is operable to create and communicate with a virtual disk  208  and or communicate data to cloud storage  108 . The virtualization module  204  can be software executed by the operating system  206  in the server  106 . However, in other configurations, the virtualization module  204  may be embodied in hardware, such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA). Further, the virtualization module  204  may be a separate function executed by a third party. An embodiment of the virtualization module  204  is shown in  FIG. 2B . 
         [0041]    The virtual disk  208  can be a logical representation of a physical storage disk, either local to the server  106  or part of the cloud  108 , and/or memory exposed to the operating system  206 . The virtual disk  208  can include information that directs the server  106  to store and/or obtain file data stored in the cloud  108 . The data stored in the cloud  108  can be file data and/or block data that can be read in and returned to operating system  206  or to the user application  202 . 
         [0042]    A user space  209  refers to the section of virtual memory used to execute user applications. A conventional operating system usually segregates virtual memory into kernel space and user space. Kernel space is reserved for running the kernel, kernel extensions, and most device drivers and user space  209  is the memory area where all user mode applications work and this memory can be swapped out when necessary. 
         [0043]    The server  106  may also include or be in communication with local storage  210 . Local storage  210  can be any type of storage media as described herein. The storage media may be organized by or be embodied as any type of database or other type of data store as described herein. The local storage  210  can store at least a portion of the data stored in the cloud  110  locally with the server  106  or in the network  104   a.  Data within the local storage  210  may be duplicated in the cloud  108 . If less than all data is stored to the cloud  108 , the portion stored within local storage  210  may be data more recently backed up. 
         [0044]    One or more application programing interfaces (APIs)  214  may communicate with one or more cloud storage vendors  218 ,  220 , and/or  226 . There may be more or fewer cloud storage vendors than those shown in  FIG. 2A  as represented by ellipses  228 . Each API  214  may communicate with a specific cloud storage vendor  218 ,  220 ,  226  to exchange data between the API  214  and the vendor  218 ,  220 ,  226 . The API can translate the data from a format used by the server  106  into a format compliant with the vendor  218 ,  220 ,  226 . Further, the API can include any routine, protocol, and/or tool that allows the server  106  to store, manage, or retrieve data stored with the vendor  218 ,  220 ,  226 . 
         [0045]    Cloud vendor storage  218 ,  220 ,  226  can include any cloud storage provided by a third party or otherwise. The cloud vendor storage  218 ,  220 ,  226  may include both the physical data storage and any interface used to interact with the data storage. Examples of the cloud vendor storage  218 ,  220 ,  226  can include Amazon cloud storage, Barracuda cloud storage, OneDrive, Dropbox, Google Drive, etc. 
         [0046]    The active directory  228  may be the file system or data storage for the users of the network  104   a.  The active directory may be a file system, for example, NFS, a Linux file system, CIFS, a Microsoft Server file system, etc. Data may be stored to the active directory  228  and then backed up to the virtual disk  208 . As such, data stored in the active directory may be stored as files comprising blocks of data. 
         [0047]    A web user interface (UI)  232  may also be provided by the server  106 . The web UI  232  may execute on the user computer  102  based on executables, hypertext markup language (HTML), extensible markup language (XML), or other code provided or provisioned from a web server  236  executing on the server  106 . The web server  236  may be a separate virtual machine operating on the server  106 , may be a separate set of hardware within the server  106 , or may be a separate device from the server  106  but in communication with the server  106 . The web server  236  allows a user  102  to access data within the virtual disk  208  or data stored at one or more vendor cloud storage  218 ,  220 ,  226 . Thus, the web server  236  may provide application functionality, via the user applications  202 , and data when the user remotely connects to the appliance  106  through an extra-enterprise network  104   b.    
         [0048]    A user quota  240   a,    240   b  can be an allocation of storage on the virtual disk  208 . The user quota  240  can be a portion of available space on the virtual disk, where each user is assigned a particular allocation. There may be more or fewer user quotas than those shown in  FIG. 2A , as represented by ellipses  244 . The user quota  240  may be similar for each user or may differ based on one or more characteristics of the user, for example, the priority of the user, the type of user, the data usage of the user, etc. 
         [0049]    A description of the data stored by a user(s), information about how, when, where, etc. of the data storage, and other information may be recorded and stored as usage log  248 . The usage log  248  may continual update as data is backed up or stored to the virtual disk  208  local storage  210 , andlor vendor storage  218 ,  220 ,  224 . The usage log  248  may be stored in local storage  210  and replicated to one or more of the vendor storages  218 ,  220 ,  224 . 
         [0050]    An embodiment of the virtualization module  204  is shown in  FIG. 2B . The disk layer interface  210  is operable to interface between the virtual disk  208  and the operating system  206  and/or user application(s)  202 . The disk layer interface  210  receives read or store requests for data from the operating system  206  and exposes the virtual disk  208  to the operating system  206 . As such, the disk layer interface  210  can provide any information or data to the operating system  206  or user application(s)  202  such that the virtual disk  208  appears as a physical disk to the local file system executed by the operating system  206 . 
         [0051]    A kernel module  212  provides the operational functionality for the virtualization module  204 . The kernel module  212  can interface with any other module in the virtualization module  204  to send or receive data. The kernel module  212  can command one or more other interface or modules within the virtualization module  204 . Thus, the kernel module  212  can organize, manage, or execute the different functions within the virtualization module  204 . 
         [0052]    A network interface  214  is operable to communicate between the server  102  and the cloud  108 . Thus, the network interface  214  can send or receive data blocks from the cloud  108 . Thus, when a file is read into the server  106 , the network interface  214  can read in blocks of data for the file and return those blocks of data to the disk layer interface  210  to be sent to the operating system  206  and/or the user application  202 . The network interface  214  may communicate with the file system in the cloud which may be network file system (NFS), a Linux file system, Common Internet File System (CIFS), a Microsoft Server file system, or other file system. 
         [0053]    A metadata engine  216  can create, modify, store, or retrieve metadata that is used to create the virtual disk and expose the virtual disk to the operating system  206 . As such, the metadata engine  210  can create a metadata wrapper for the file system and each file stored within the virtual disk  208 . In an embodiment, the file system used by the operating system  206  may be New Technology File System (NTFS), a Windows NT file system, may require a master file table that may be stored in the virtualization master file table database  224 . The master file table will be described herein after but one skilled in the art will understand the other metadata that may be required in the “master file table” if another file system is used, such as third extended file system (EXT3), a Linux file system, or another file system. The metadata engine provides the metadata required to expose the virtual disk  208  to the operating system  206 . 
         [0054]    A directory organization module  218  can provide the data required to give a directory structure to the virtual disk  208 . The directory structure provides a root directory and then one or more subdirectories that can organize the files within the virtual disk  208 . Thus, the files, stored within the virtual disk  208 , are managed similar to an actual physical disk. Further, a hierarchy of directories and files can be exposed to the file system used by the operating system  206 . 
         [0055]    An operating system (OS) interface  220  can provide the hooks or pointers from the operating system commands to the virtual disk  208 . For example, if an operating system attempts to write information to the virtual disk  208 , the operating system interface  220  can intercept those commands and provide the commands to the disk layer interface  210  to be executed with the virtual disk  208 . Further, any write commands, read commands, or other commands may he intercepted or sent between the virtualization module  204  and the operating system  206  by the operating system interface  220 , such that the operating system interface  220  provides the appearance, to the operating system  206 , that the virtual disk  208  is an actual physical disk in the local computer system. 
         [0056]    A boot module  222  provides the jumps, pointers, links, metadata, and different operating requirements to use the virtual disk  208  as a boot disk. A boot disk is used to boot the server  106  at start-up or during other occasions. The boot module  222  provides the specific functionality for booting the server  102  from the virtual disk  208 . 
         [0057]    The virtualization module  204  may also include a script layer  250 . The script layer  250  can communicate with one or more users  102  to conduct backup operations. Once the appliance  106  is incorporated with the Active Directory  228  in the network  104 a, users can upload and/or download files to the appliance  104   a  using standard network protocols, like CIFS or NFS. The script layer can conduct these data transactions, and the appliance  104  can create a record, in the usage log  248 , for audit, history and billing purposes. As data is transferred to the appliance  106 , via backup software or manually, the script layer  250  may run an asynchronous schedule that takes ZFS snapshots. Thus, versions of files and backups happen automatically on the appliance  106 . A counterpart to the appliance  106  can exist in the cloud  108 , which can be created with an identical file-system. Periodically, the script layer can copy the local snapshot, with incremental changes to the remote cloud file system. Thus the cloud appliance will have a second copy of all data. In some configuration all transfers are incremental and encrypted. Further, data in the cloud  108  may be encrypted on the cloud  108 . 
         [0058]    Finally, the virtualization master file table database  224  contains the one or more master file tables that store the metadata created by the metadata engine  216  and used by the one or more other modules or interfaces. The virtualization master file table (MFT) database  224  can be any type of storage or data system that exposes data, stores data, retrieves data, or modifies data for one or more components. The virtualization MFT database  224  can store one or more MFT tables as described in conjunction with  FIG. 3 . 
         [0059]    An embodiment of a data storage process  300  for managing data in the cloud  108  by creating metadata  312  associated with the data is shown in  FIG. 3A . The metadata/code data structure  312  can be stored in several different forms or in different types of databases or data storage systems, such as relational databases, flat files, object-oriented databases, etc. Thus, while the term “data field” or segment” is used, the data may be stored in an object, an attribute of an object, or some other form of data structure. Further, at least portions of the metadata/code data structure  312  can be stored, retrieved, sent, or received during the operation of the virtual disk by the server  106  or the user computer  102 . The metadata/code data structure  312  stores one or more items of information in one or more data fields. The data in the metadata/code data structure  312  can be as described in conjunction with  FIG. 3C . The metadata/code data structure  312  may be generated and/or updated by the server  106  and/ or user  102  during storage of back up data and saved either in the virtual disk  208  and/or the cloud  108 . 
         [0060]    As is shown in  FIG. 3B , there may be duplicate copies of the metadata/code data structure  312  shown as local metadata  324  and/or cloud metadata  328  maintained in a synchronization scheme  320 . The local metadata  324  and/or cloud metalata  328  may also be as described in conjunction with  FIG. 3C . During storage, the local metadata  324  and/or cloud metadata  328  may be formed and saved in local storage  210  and also in each of the vendor cloud storage  218 ,  222 ,  226 . Changes to local metadata  324  may be synchronized to update the copies in each of the vendor cloud storage  218 ,  222 ,  226  to maintain like copies of the metadata. 
         [0061]    The data structure  332  for storing data across the vendor cloud storages  218 ,  222 ,  226  may be as shown in  FIG. 3C . Each of the vendor cloud storage  218 ,  222 ,  226  can include a separate data store having one or more fields, that may include, but is not limited to, metadata  302  (which may be the same or similar to the metadata/code data structure  312 ), backed up data  304 , and/or a file extents  306 . There may be more or fewer fields in the data as represented by ellipses  307 . Further, there may be more or fewer cloud storage vendors than those shown in  FIG. 3C , as represented by ellipses  322 . 
         [0062]    A separate metadata file  302  may be created and updated. The metadata file  302  may remain both in memory and cached locally  210  as well as cached on all available providers  218 ,  22 ,  226 . The metadata file  302  can contain the mapping between logical blocks on the device and the location of the blocks within files A-1, B-1, C-1, etc. The first file that is created on each provider  218 ,  22 ,  226  may be the metadata file  302 . The metadata file  302  can also be created and cached locally in storage  210 . In at least some configurations, a memory mapped file is used for the metadata file  302  by the mapping script layer  250  that stores the data into the cloud  108 . 
         [0063]    As blocks get written to the cloud  108 , the server  106  can pack the blocks into available space in the file A-1, B-1, etc. A single block can reside at multiple locations, within and across many providers  218 ,  22 ,  226 . This storage and duplication is controlled, by the script layer  250 , at creation time for both redundancy and performance reasons. As blocks are written, the script layer  250  can pack the blocks sequentially and a densely as possible, until the blocks reach the extent boundary of the storage. 
         [0064]    The metadata file  302  can thus include data for a start address, a block length, a unique ID, and/or a checksum. The unique ID may be a computationally unique, monotonically increasing sequence, which is assigned to each write at the end of completion of a single set of sequential writes—although other types of IDs are possible. The unique ID may identify the block or set of blocks written and can tag the block or set of blocks with a sequence number, which can help in determining the write-order. The unique ID may also be constructed with a high granularity timestamp so that the write time for each segment can be determined later. No writes may overwrite any existing writes, older writes can be purged as part of a different process to be described later. The unique IDs may be listed in a separate file called $UNIQUE&lt;id&gt; which can have quintuplets: unique ID, provider, file, start address, and/or write or block length. Unique IDs may be repeated if files are redundantly stored, within and across providers  218 ,  220 ,  226 . 
         [0065]    The checksum is optional and computed efficiently from the in memory write buffer and recorded as part of the metadata file  302 . The data  304  includes any blocks written to the providers  218 ,  220 ,  226 . File extents  306  can include the address or length of available storage capacity in the provider  218 ,  220 ,  226 . 
         [0066]    An embodiment of a process or method  400  for creating cloud storage is shown in  FIG. 4 . Generally, the method  400  begins with a start operation  404  and terminates with an end operation  440 . While a general order for the steps of the method  400  are shown in  FIG. 4 , the method  400  can include more or fewer steps or arrange the order of the steps differently than those shown in  FIG. 4 . The method  400  can be executed as a set of computer-executable instructions executed by a computer system and encoded or stored on a computer readable medium. Hereinafter, the method  400  shall be explained with reference to the systems, components, modules, software, data structures, etc. described in conjunction with  FIGS. 1-3C . 
         [0067]    A user computer  102  logins in to the portal of the server  106 , in step  408 . If it is the first login by a user, that user is identified as a special administrator user and has special privileges and will be allowed to setup and configure the appliance  106 . Generally, the user  102  can login through the user space  209  or the web server  236  via a web UI  232 . 
         [0068]    The server  106  may then authenticate the user against the Active Directory  228 , in step  412 . If the user is registering, a script layer  250  can execute, on the web server  236 , a script to create a user account, a user quota  240  (space) inside the appliance  106 , and a full local configuration for the user. 
         [0069]    The appliance  106  may then add itself as a member of the local network  104   a  with a domain account (with domain join rights) using the available corporate Active Directory  104   a / 228 , in step  416 . 
         [0070]    Once the appliance  106  is part of the Active Directory network  104   a / 228 , authenticated users may upload and/or download files to the appliance  106  using standard network protocols, like CIFS or NFS, in step  420 . As these transactions take place within the appliance  106 , a usage record  248  is made for audit, history, and/or billing purposes. 
         [0071]    As data is transferred from the user  104  to the appliance  106 , via backup software or manually, the script layer  250  runs an asynchronous schedule taking ZFS snapshots, in step  424 . Thus, versions of files and backups can happen automatically on the appliance  106 . 
         [0072]    An appliance counterpart may exist in the cloud  108 , which can be created with an identical file-system, in step  428 . Periodically, the local appliance snapshot would copy incremental changes to the remote ‘cloud’ appliance  108 . Thus, the cloud appliance  108  can have a second copy of all data. The transfers can be incremental and encrypted. Further, the data can also be stored as encrypted data on the remote appliance  108 . 
         [0073]    In some configurations, the script layer may execute a purge script periodically to remove older snapshots from the local appliance to free up space, in step  432 . The purge script may make sure that the corresponding snapshot exists on the cloud appliance  108 . 
         [0074]    Further, the server  106  or cloud appliance  108  also copy data “sideways” or duplicate data to other remote storage vendors  218 ,  222 ,  226 , like Microsoft and Nirvanix to create automatic copies of data between providers, in step  436 . 
         [0075]    An embodiment of a process or method  500  for writing data to the cloud is shown in  FIG. 5 . Generally, the method  500  begins with a start operation  504  and terminates with an end operation  536 . While a general order for the steps of the method  500  are shown in  FIG. 5 , the method  500  can include more or fewer steps or arrange the order of the steps differently than those shown in  FIG. 5 . The method  500  can be executed as a set of computer-executable instructions executed by a computer system and encoded or stored on a computer readable medium. Hereinafter, the method  500  shall be explained with reference to the systems, components, modules, software, data structures, etc. described in conjunction with  FIGS. 1-4 . 
         [0076]    The disk layer interface  210  can wait until a local buffer is full or an idle write timeout is reached, in step  508  The script layer  250  may then find an empty slot on a randomly selected storage provider  218 ,  222 ,  226 , by looking at last extent written  306  (the last extent written may be updated as part of a write), in step  512 . The script layer  250  may then automatically write blocks to the end of the last empty slot, in step  516 . 
         [0077]    The metadata engine  216  may then update the metadata file  302  and unique ID file, in step  520 , for the provider  218 ,  222 ,  226  to which data was written. The script layer  250  can then return success to the virtual disk layer  210 , in step  524 . 
         [0078]    The script layer  250  may also determine if redundancy is required for the data. If redundancy is required, then the script layer can write asynchronously from the main writing thread to as many other storage providers  218 ,  222 ,  226 , as required by the redundancy level, in optional step  528 . Further, the metadata engine  216  may also optionally update metadata  302  and unique IDs for each redundant provider  218 ,  222 ,  226 , in step  532 . 
         [0079]    An embodiment of a process or method  600  for reading from cloud storage is shown in  FIG. 6 . Generally, the method  600  begins with a start operation  602  and terminates with an end operation  616 . While a general order for the steps of the method  600  are shown in  FIG. 6 , the method  600  can include more or fewer steps or arrange the order of the steps differently than those shown in  FIG. 6 . The method  600  can be executed as a set of computer-executable instructions executed by a computer system and encoded or stored on a computer readable medium. Hereinafter, the method  600  shall be explained with reference to the systems, components, modules, software, data structures, etc. described in conjunction with  FIGS. 1-5 . 
         [0080]    A metadata engine  216  or other module can search metadata  302  (which is memory mapped and sorted by offsets) for matching offset(s) associated with blocks in a file, in step  608 . The metadata engine  216  may then follow the unique ID found in the search to find the unique IDs on all configured providers  218 ,  222 ,  226  substantially simultaneously, in step  612 . In some configurations, the search is optimized by first finding the largest unique ID by going to the end of the file. Since unique IDs can be monotonically increasing, if a unique ID being searched is greater than the last unique ID in a file, this situation indicates that a next unique ID file needs to be searched. 
         [0081]    Whichever search thread returns first from a provider  218 ,  222 ,  226 , the script layer  250  determines the provider, file, start, length, and the other threads are terminated. A read is then initiated from the designated provider, file, offset for the required length, in step  616 . The search process can also be initiated with a time range as input, in which case, all unique IDs in that range are returned. This type of search allows for block versioning and needs file-system or layered driver support to present versions or snapshots to the user layer. 
         [0082]    An embodiment of a process or method  700  for purging cloud data is shown in  FIG. 7 . Generally, the method  700  begins with a start operation  704  and terminates with an end operation  724 . While a general order for the steps of the method  700  are shown in  FIG. 7 , the method  700  can include more or fewer steps or arrange the order of the steps differently than those shown in  FIG. 7 . The method  700  can be executed as a set of computer-executable instructions executed by a computer system and encoded or stored on a computer readable medium. Hereinafter, the method  700  shall be explained with reference to the systems, components, modules, software, data structures, etc. described in conjunction with  FIGS. 1-6 . 
         [0083]    A periodic purge process can runs on the cloud data (at a lower priority than read and write threads), where a script layer thread can examine space utilization against space utilization thresholds on each provider, in step  708 . Here, the script determines if that amount of space being used is approaching the maximum allotted space or some other benchmark. The thread from the script layer  250  then examines the unique ID files that are candidates for deletion of blocks, in step  712 . No blocks are deleted if there is no advance copy of data for that block, i.e. , the same block has a larger unique ID. If all segments of a file on a device  106  is found marked for deletion, the entire file may be deleted and the unique ID file updated to reflect the changes. Unique ID entries can have the length attribute set to zero if the entry has been purged, to indicate it as a stale unique ID. 
         [0084]    Potentially, over time, there will be files which have “holes” (blocks stored in sectors or areas that are not continuous) but cannot be deleted because the file contains some unique ID which has not changed since the data was written and no redundant copy for that block exists. In this situation, the small set of blocks that have to preserved can be copied to the latest file on the provider  106  (with a new unique ID pointing to the copied version of data), and the script layer thread  250  can delete the old provider file in its entirety, in optional step  716 . After determining which blocks to delete, the script layer thread  250  can purge or delete the identified or marked blocks, in step  720 . The unique ID files themselves may be candidates for removal as entries get stale and can be deleted in their entirety when all entries are stale or when most entries are stale and the remaining entries are copied up to a newer unique ID file. 
         [0085]    An embodiment of a process or method  800  for de-duplicating cloud data is shown in  FIG. 8 . Generally, the method  800  begins with a start operation  804  and terminates with an end operation  820 . While a general order for the steps of the method  800  are shown in  FIG. 8 , the method  800  can include more or fewer steps or arrange the order of the steps differently than those shown in  FIG. 8 . The method  800  can be executed as a set of computer-executable instructions executed by a computer system and encoded or stored on a computer readable medium. Hereinafter, the method  800  shall be explained with reference to the systems, components, modules, software, data structures, etc. described in conjunction with  FIGS. 1-7 . 
         [0086]    A thread in the script layer  250  can also complete efficient de-duplication as part of the purge process. The thread can compare checksums between two or more files or blocks during an examination process, in step  808 . If two files or blocks with identical checksums are located, the thread can replace the provider, file, start, length, pointed to by a unique ID, by another unique ID set with identical checksum, in step  812 . Then, the thread can set to zero the original block&#39;s unique ID, which renders the original block an automatic candidate for deletion during further purging. 
         [0087]    An embodiment of a process or method  900  for resurrecting an alternate personality with cloud data is shown in  FIG. 9 . Generally, the method  900  begins with a start operation  904  and terminates with an end operation  956 . While a general order for the steps of the method  900  are shown in  FIG. 9 , the method  900  can include more or fewer steps or arrange the order of the steps differently than those shown in  FIG. 9 . The method  900  can be executed as a set of computer-executable instructions executed by a computer system and encoded or stored on a computer readable medium. Hereinafter, the method  900  shall be explained with reference to the systems, components, modules, software, data structures, etc. described in conjunction with  FIGS. 1-8 . 
         [0088]    Existing user data available via the appliance  106  may be presented to users who are authenticated and are valid users of the data via a combination of, for example, hypervisor+JEOS+applications+userdata. JEOS refers to an open source which contains just enough as code to run the set of applications which would be able to interpret and present the data to the end-user for active use. For example, the simplest case of a user wanting a version of an Excel file from Thursday that he wants to work on, at a remote location away from the network  104   a.  The user can use a computer or kiosk and enter a self-service portal. From the self-service portal, the user can be presented a copy of Linux+Open Office+the Excel file from Thursday that he needs to work on. The work space can then be saved, discarded, or refreshed with additional data. The changed file may be made permanent or exist as a new version. 
         [0089]    A server  106  receives a connection from a user computer  102  through a web server  236  in communication with a web UI  232 , in step  908 . The web server  236  functions as a portal to allow the user computer  102  to authenticate itself with the server  106 . After authentication, the user space  209  presents the user&#39;s data to the user through the web server  236 , in step  912 . The user space  209  can receive a selection of a subset of the data and any requests activation through the web server  236 , in step  916 . 
         [0090]    If activation is received, the user space  209  may then receive a choice of execution environment from the user computer  102 , in step  920 . The user has the option of running an application on a local hypervisor (available on the kiosk, temporary workstation, or personal laptop), on a pay-as-you-go cloud workstation, or on the appliance  106  itself. 
         [0091]    Upon selection of the environment, the activation process starts to determine which application to use with the data, in step  924 . The data is examined to determine which open-source applications could best serve the data. A catalog is kept of associations between file types and applications. (This is refreshed periodically from the internet database of mime-types etc.) 
         [0092]    The user space  209  may then obtain an open source as an image from the catalog which is most compatible with the application, in step  928 . In at least some configurations, both the compatibility matrix and open source OS are periodically examined by searching the Internet to determine the best match between application and OS image. Further, an operator could mediate this process periodically and/or, manually to super cede or fine tune the automatic selection process. The user space  209  may then automatically install the application or set of applications on the OS, in step  932 . (The installation process may be optimized by examining a local cache within the appliance  106  which contains a least recently used OS+application combination. If a cache hit occurs, the image can be used as is.) 
         [0093]    The user space may create or receive a writeable copy of user data-set by invoking an available copy-on-write technology, in step  936 . The writeable copy of user-data may then be connected, by the user space  209 , to the OS image, as a remote file-system, in step  940 . Since the OS image could be running remotely or co-located, the connection prevents delays or errors in using the data. 
         [0094]    The user computer  102  or appliance  106  may then execute, view, or modify the application, OS, and/or data locally on the hypervisor available on the appliance  106 , or as streamed to a workstation that the user has initiated the session from, or from a remote execution platform like Amazon AWS or Windows Azure, in step  944 . The last execution plan requires bundling and copying the image to a remote store. The bundling is very quick since the image contains just enough OS+executables and is small in size. 
         [0095]    The user can now view and modify the data during the session. Upon ending the session, the user computer  102  and/or appliance can complete an end-of-session process, in step  948 . At the end of the session, the user can email the document, save the session for a fixed number of days, persist the changed version of data, or discard the session completely. In some configurations, the entire user session can be audited to very exacting detail and the audit trail made available by administrators using the appliance, in step  952 . 
         [0096]      FIG. 10  illustrates a block diagram of a computing environment  1000  that may function as the servers, user computers, or other systems provided and described above. The environment  1000  includes one or more user computers  1005 ,  1010 , and  1015 . The user computers  1005 ,  1010 , and  1015  may be general purpose personal computers (including, merely by way of example, personal computers, and/or laptop computers running various versions of Microsoft Corp.&#39;s Windows™ and/or Apple Corp.&#39;s Macintosh™ operating systems) and/or workstation computers running any of a variety of commercially-available UNIX™ or UNIX-like operating systems. These user computers  1005 ,  1010 ,  1015  may also have any of a variety of applications, including for example, database client and/or server applications, and web browser applications. Alternatively, the user computers  1005 ,  1010 , and  1015  may be any other electronic device, such as a thin-client computer, Internet-enabled mobile telephone, and/or personal digital assistant, capable of communicating via a network  1020  and/or displaying and navigating web pages or other types of electronic documents. Although the exemplary computer environment  1000  is shown with three user computers, any number of user computers may be supported. 
         [0097]    Environment  1000  further includes a network  1020 . The network  1020  may can be any type of network familiar to those skilled in the art that can support data communications using any of a variety of commercially-available protocols, including without limitation SIP, TCP/IP, SNA, IPX, AppleTalk, and the like. Merely by way of example, the network  1020  maybe a local area network (“LAN”), such as an Ethernet network, a Token-Ring network and/or the like; a wide-area network; a virtual network, including without limitation a virtual private network (“VPN”); the Internet; an intranet; an extranet; a public switched telephone network (“PSTN”); an infra-red network; a wireless network (e.g., a network operating under any of the IEEE 802.11 suite of protocols, the Bluetooth™ protocol known in the art, and/or any other wireless protocol); and/or any combination of these and/or other networks. 
         [0098]    The system may also include one or more server  1025 ,  1030 . In this example, server  1025  is shown as a web server and server  1030  is shown as an application server. The web server  1025 , which may be used to process requests for web pages or other electronic documents from user computers  1005 ,  1010 , and  1015 . The web server  1025  can be running an operating system including any of those discussed above, as well as any commercially-available server operating systems. The web server  1025  can also run a variety of server applications, including SIP servers, HTTP servers, FTP servers, CGI servers, database servers, Java servers, and the like. In some instances, the web server  1025  may publish operations available operations as one or more web services. 
         [0099]    The environment  1000  may also include one or more file and or/application servers  1030 , which can, in addition to an operating system, include one or more applications accessible by a client running on one or more of the user computers  1005 ,  1010 ,  1015 . The server(s)  1030  and/ or  1025  may be one or more general purpose computers capable of executing programs or scripts in response to the user computers  1005 ,  1010  and  1015 . As one example, the server  1030 ,  1025  may execute one or more web applications. The web application may be implemented as one or more scripts or programs written in any programming language, such as Java™, C, C#™, or C++, and/or any scripting language, such as Perl, Python, or TCL, as well as combinations of any programming/scripting languages. The application server(s)  1030  may also include database servers, including without limitation those commercially available from Oracle, Microsoft, Sybase™, IBM™ and the like, which can process requests from database clients running on a user computer  1005 . 
         [0100]    The web pages created by the server  1025  and/or  1030  may be forwarded to a user computer  1005  via a web (file) server  1025 ,  1030 . Similarly, the web server  1025  may be able to receive web page requests, web services invocations, and/or input data from a user computer  1005  and can forward the web page requests and/or input data to the web (application) server  1030 . In further embodiments, the web server  1030  may function as a file server. Although for ease of description,  FIG. 10  illustrates a separate web server  1025  and file/application server  1030 , those skilled in the art will recognize that the functions described with respect to servers  1025 ,  1030  may be performed by a single server and/or a plurality of specialized servers, depending on implementation-specific needs and parameters. The computer systems  1005 ,  1010 , and  1015 , web (file) server  1025  and/or web (application) server  1030  may function as the system, devices, or components described in  FIGS. 1-3C . 
         [0101]    The environment  1000  may also include a database  1035 . The database  1035  may reside in a variety of locations. By way of example, database  1035  may reside on a storage medium local to (and/or resident in) one or more of the computers  1005 ,  1010 ,  1015 ,  1025 ,  1030 . Alternatively, it may be remote from any or all of the computers  1005 ,  1010 ,  1015 ,  1025 ,  1030 , and in communication (e.g, via the network  1020 ) with one or more of these. The database  1035  may reside in a storage-area network (“SAN”) familiar to those skilled in the art. Similarly, any necessary files for performing the functions attributed to the computers  1005 ,  1010 ,  1015 ,  1025 ,  1030  may be stored locally on the respective computer and/or remotely, as appropriate. The database  1035  may be a relational database, such as Oracle 10i™, that is adapted to store, update, and retrieve data in response to SQL-formatted commands. 
         [0102]      FIG. 11  illustrates one embodiment of a computer system  1100  upon which the servers, user computers, or other systems or components described above may be deployed or executed. The computer system  1100  is shown comprising hardware elements that may be electrically coupled via a bus  1155 . The hardware elements may include one or more central processing units (CPUs)  1105 ; one or more input devices  1110  (e.g., a mouse, a keyboard, etc.); and one or more output devices  1115  (e.g., a display device, a printer, etc.). The computer system  1100  may also include one or more storage devices  1120 . By way of example, storage device(s)  1120  may be disk drives, optical storage devices, solid-state storage devices such as a random access memory (“RAM”) and/or a read-only memory (“ROM”), which can be programmable, flash-updateable and/or the like. 
         [0103]    The computer system  1100  may additionally include a computer-readable storage media reader  1125 ; a communications system  1130  (e.g., a modem, a network card (wireless or wired), an infra-red communication device, etc.); and working memory  1140 , which may include RAM and ROM devices as described above. The computer system  1100  may also include a processing acceleration unit  1135 , which can include a DSP, a special-purpose processor, and/or the like. 
         [0104]    The computer-readable storage media reader  1125  can further be connected to a computer-readable storage medium, together (and, optionally, in combination with storage device(s)  1120 ) comprehensively representing remote, local, fixed, and/or removable storage devices plus storage media for temporarily and/or more permanently containing computer-readable information. The communications system  1130  may permit data to be exchanged with the network  1020  ( FIG. 10 ) and/or any other computer described above with respect to the computer system  1100 . Moreover, as disclosed herein, the term “storage medium” may represent one or more devices for storing data, including read only memory (ROM), random access memory (RAM), magnetic RAM, core memory, magnetic disk storage mediums, optical storage mediums, flash memory devices and/or other machine readable mediums for storing information. 
         [0105]    The computer system  1100  may also comprise software elements, shown as being currently located within a working memory  1140 , including an operating system  1145  and/or other code  1150 . It should be appreciated that alternate embodiments of a computer system  1100  may have numerous variations from that described above. For example, customized hardware might also be used and/or particular elements might be implemented in hardware, software (including portable software, such as applets), or both. Further, connection to other computing devices such as network input/output devices may be employed. 
         [0106]    In the foregoing description, for the purposes of illustration, methods were described in a particular order. It should be appreciated that in alternate embodiments, the methods may he performed in a different order than that described. It should also be appreciated that the methods described above may be performed by hardware components or may be embodied in sequences of machine-executable instructions, which may be used to cause a machine, such as a general-purpose or special-purpose processor or logic circuits programmed with the instructions to perform the methods. These machine-executable instructions may be stored on one or more machine readable mediums, such as CD-ROMs or other type of optical disks, floppy diskettes, ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, flash memory, or other types of machine-readable mediums suitable for storing electronic instructions. Alternatively, the methods may be performed by a combination of hardware and software. 
         [0107]    Specific details were given in the description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments. 
         [0108]    Also, it is noted that the embodiments were described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in the figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function. 
         [0109]    Furthermore, embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine readable medium such as storage medium. A processor(s) may perform the necessary tasks. A code segment may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc. 
         [0110]    While illustrative embodiments of the invention have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such Variations, except as limited by the prior art.