Abstract:
A method for backing up data is disclosed. In one embodiment, such a method includes sending, from a host system to a storage system, a first request to make a logical point-in-time copy of production data on the storage system. The storage system executes the first request by creating the logical point-in-time copy thereon. An identifier is assigned to the logical point-in-time copy. The method further sends, from the host system to the storage system, a second request to directly copy a specified portion of data in the logical point-in-time copy to cloud storage. The second request identifies the logical point-in-time copy using the identifier. The storage system executes the second request by directly copying the specified portion from the logical point-in-time copy to the cloud storage. A corresponding system and computer program product are also disclosed.

Description:
BACKGROUND 
       [0001]    Field of the Invention 
         [0002]    This invention relates to systems and methods for backing up data, particularly to cloud-based storage systems. 
         [0003]    Background of the Invention 
         [0004]    Today, when backing up production data residing on a storage system, the Concurrent Copy function may be used to reduce the amount of time that production data is unavailable to applications. In particular, the Concurrent Copy function may be used to generate, on the storage system, a logical point-in-time copy of the production data by creating a side file that tracks changes to the production data after the logical point-in-time copy is created. Once the logical point-in-time copy is created, a backup process (executing on a host system) may be used to back up the point-in-time copy to backup storage. This frees up the production data for access by other applications. The backup process may read and back up data directly from the production data for data that has not changed since creation of the logical point-in-time copy. By contrast, the backup process may read and back up data from the side file for data that has changed since creation of the logical point-in-time copy. 
         [0005]    Current implementations of Concurrent Copy limit the amount of data that can be stored in cache of the storage system. For example, if more than sixty percent of the cache is occupied by the side file, the remainder of the side file may need to be stored in virtual storage (i.e., memory) of the host system. This may create additional overhead to locate and back up data in the side file. Another drawback of Concurrent Copy and other point-in-time copy functions is that these functions typically cannot be used to back up production data to cloud storage. Rather, when backing up production data to cloud storage, the production data typically has to be serialized (locked) and copied to backup storage before the production data can be unlocked and accessed by other applications. 
         [0006]    In view of the foregoing, what are needed are systems and methods to more efficiently back up production data, particularly to cloud-based storage systems. Further needed are systems and methods to utilize point-in-time copy functions such as Concurrent Copy when backing up production data to cloud-based storage systems. 
       SUMMARY 
       [0007]    The invention has been developed in response to the present state of the art and, in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available systems and methods. Accordingly, the invention has been developed to provide systems and methods to more effectively back up data, particularly to cloud-based storage systems. The features and advantages of the invention will become more fully apparent from the following description and appended claims, or may be learned by practice of the invention as set forth hereinafter. 
         [0008]    Consistent with the foregoing, a method for backing up data is disclosed herein. In one embodiment, such a method includes sending, from a host system to a storage system, a first request to make a logical point-in-time copy of production data on the storage system. The storage system executes the first request by creating the logical point-in-time copy thereon. An identifier is assigned to the logical point-in-time copy. The method further sends, from the host system to the storage system, a second request to directly copy a specified portion of data in the logical point-in-time copy to cloud storage. The second request identifies the logical point-in-time copy using the identifier. The storage system executes the second request by directly copying the specified portion from the logical point-in-time copy to the cloud storage. 
         [0009]    A corresponding system and computer program product are also disclosed and claimed herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through use of the accompanying drawings, in which: 
           [0011]      FIG. 1  is a high-level block diagram showing an exemplary environment in which embodiments of the invention may operate; 
           [0012]      FIG. 2  is a high-level block diagram showing one embodiment of a storage system in which embodiments of the invention may operate; 
           [0013]      FIG. 3  is a high-level block diagram showing various modules that may be used to implement systems and methods in accordance with the invention; 
           [0014]      FIG. 4  is a high-level block diagram showing a first request, transmitted from a host system to a storage system, to create a logical point-in-time copy on the storage system; 
           [0015]      FIG. 5  is a high-level block diagram showing an acknowledgement, transmitted from the storage system to the host system, indicating that the logical point-in-time copy has been created; 
           [0016]      FIG. 6  is a high-level block diagram showing a second request, transmitted from the host system to the storage system, to back up the logical point-in-time copy to backup storage; and 
           [0017]      FIG. 7  is a high-level block diagram showing an acknowledgement, transmitted from the storage system to the host system, indicating that the backup of the logical point-in-time copy is complete; 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    It will be readily understood that the components of the present invention, as generally described and illustrated in the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the invention, as represented in the Figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of certain examples of presently contemplated embodiments in accordance with the invention. The presently described embodiments will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. 
         [0019]    The present invention may be embodied as a system, method, and/or computer program product. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions stored thereon for causing a processor to carry out aspects of the present invention. 
         [0020]    The computer readable storage medium may be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire. 
         [0021]    Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device. 
         [0022]    Computer-readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages. 
         [0023]    The computer readable program instructions may execute entirely on a user&#39;s computer, partly on a user&#39;s computer, as a stand-alone software package, partly on a user&#39;s computer and partly on a remote computer, or entirely on a remote computer or server. In the latter scenario, a remote computer may be connected to a user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention. 
         [0024]    Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, may be implemented by computer-readable program instructions. 
         [0025]    These computer-readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer-readable program instructions may also be stored in a computer-readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer-readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks. 
         [0026]    The computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer-implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks. 
         [0027]    Referring to  FIG. 1 , one example of a network environment  100  is illustrated. The network environment  100  is presented to show one example of an environment where systems and methods in accordance with the invention may be implemented. The network environment  100  is presented only by way of example and not limitation. Indeed, the systems and methods disclosed herein may be applicable to a wide variety of network environments, in addition to the network environment  100  shown. 
         [0028]    As shown, the network environment  100  includes one or more computers  102 ,  106  interconnected by a network  104 . The network  104  may include, for example, a local-area-network (LAN)  104 , a wide-area-network (WAN)  104 , the Internet  104 , an intranet  104 , or the like. In certain embodiments, the computers  102 ,  106  may include both client computers  102  and server computers  106  (also referred to herein as “host systems”  106 ). In general, the client computers  102  initiate communication sessions, whereas the server computers  106  wait for requests from the client computers  102 . In certain embodiments, the computers  102  and/or servers  106  may connect to one or more internal or external direct-attached storage systems  112  (e.g., arrays of hard-disk drives, solid-state drives, tape drives, etc.). These computers  102 ,  106  and direct-attached storage systems  112  may communicate using protocols such as ATA, SATA, SCSI, SAS, Fibre Channel, or the like. 
         [0029]    The network environment  100  may, in certain embodiments, include a storage network  108  behind the servers  106 , such as a storage-area-network (SAN)  108  or a LAN  108  (e.g., when using network-attached storage). This network  108  may connect the servers  106  to one or more storage systems  110 , such as arrays  110   a  of hard-disk drives or solid-state drives, tape libraries  110   b , individual hard-disk drives  110   c  or solid-state drives  110   c , tape drives  110   d , CD-ROM libraries, or the like. To access a storage system  110 , a host system  106  may communicate over physical connections from one or more ports on the host  106  to one or more ports on the storage system  110 . A connection may be through a switch, fabric, direct connection, or the like. In certain embodiments, the servers  106  and storage systems  110  may communicate using a networking standard such as Fibre Channel (FC). 
         [0030]    Referring to  FIG. 2 , one embodiment of a storage system  110   a  containing an array of hard-disk drives  204  and/or solid-state drives  204  is illustrated. As shown, the storage system  110   a  includes a storage controller  200 , one or more switches  202 , and one or more storage devices  204 , such as hard disk drives  204  or solid-state drives  204  (such as flash-memory-based drives  204 ). The storage controller  200  may enable one or more hosts  106  (e.g., open system and/or mainframe servers  106  running operating systems such as MVS, z/OS, or the like) to access data in the one or more storage devices  204 . 
         [0031]    In selected embodiments, the storage controller  200  includes one or more servers  206 . The storage controller  200  may also include host adapters  208  and device adapters  210  to connect the storage controller  200  to host devices  106  and storage devices  204 , respectively. Multiple servers  206   a ,  206   b  may provide redundancy to ensure that data is always available to connected hosts  106 . Thus, when one server  206   a  fails, the other server  206   b  may pick up the I/O load of the failed server  206   a  to ensure that I/O is able to continue between the hosts  106  and the storage devices  204 . This process may be referred to as a “failover.” 
         [0032]    In selected embodiments, each server  206  may include one or more processors  212  and memory  214 . The memory  214  may include volatile memory (e.g., RAM) as well as non-volatile memory (e.g., ROM, EPROM, EEPROM, hard disks, flash memory, etc.). The volatile and non-volatile memory may, in certain embodiments, store software modules that run on the processor(s)  212  and are used to access data in the storage devices  204 . The servers  206  may host at least one instance of these software modules. These software modules may manage all read and write requests to logical volumes in the storage devices  204 . 
         [0033]    One example of a storage system  110   a  having an architecture similar to that illustrated in  FIG. 2  is the IBM DS8000™ enterprise storage system. The DS8000™ is a high-performance, high-capacity storage controller providing disk storage that is designed to support continuous operations. Nevertheless, the systems and methods disclosed herein are not limited to operation with the IBM DS8000™ enterprise storage system  110   a , but may operate with any comparable or analogous storage system  110 , regardless of the manufacturer, product name, or components or component names associated with the system  110 . Furthermore, any storage system that could benefit from one or more embodiments of the invention is deemed to fall within the scope of the invention. Thus, the IBM DS8000™ is presented only by way of example and is not intended to be limiting. 
         [0034]    Referring to  FIG. 3 , as previously mentioned, in certain environments, point-in-time copy technologies such as Concurrent Copy may be used to back up production data  318  stored on a storage system  110 . Unfortunately, point-in-time copy technologies such as Concurrent Copy typically cannot be used to back up data to cloud storage. Furthermore, most backup processes require involvement by host systems  106 , namely to read data from point-in-time copies on a storage system  110   e , and write the data to a backup storage system  110   f . This can impose a significant amount of additional stress and overhead on host systems  106 . 
         [0035]    In order to address the deficiencies identified above, a backup module  308  may be implemented within a storage system  110   e  (which may include, for example, a disk array  110   a  or other suitable storage system  110 ) to backup data stored thereon. This backup module  308  may work in conjunction with a point-in-time-copy module  304  to back up production data  318  to a backup storage system  110   f  (which may include, for example, a disk array  110   a  or other suitable storage system  110 ) while limiting the amount of time that the production data  318  is unavailable for access by other applications. The production data  318  include all production data  318  on the storage system  110   e  or, in other embodiments, certain volumes or portions of production data  318  on the storage system  110   e.    
         [0036]    To implement such a system and method, one or more modules may be present the storage system  110   e  as well as a host system  106  accessing the storage system  110   e . For example, the host system  106  may include one or more of a copy request module  322 , identifier generation module  324 , backup request module  326 , copy identification module  328 , and portion identification module  330 . The storage system  110   e  may include an update module  306  in addition to the point-in-time-copy module  304  and backup module  308  previously discussed. These modules may be implemented in software, hardware, firmware, or a combination thereof. 
         [0037]    In operation, the copy request module  322  on the host system  106  may generate a request to create a point-in-time copy  320  of production data  318  on the storage system  110   e . Similarly, the identifier generation module  324  may generate an identifier (e.g., session ID, number, object name, etc.) associated with the point-in-time copy  320 . The request along with the identifier may be transmitted to the storage system  110   e . In response to the request, the point-in-time-copy module  304  may generate the point-in-time copy  320  of the production data  318  with the provided identifier. The identifier may be used to identify the point-in-time copy  320  as well as differentiate the point-in-time copy  320  from other point-in-time copies  320  that may be present on the storage system  110   e.    
         [0038]    The point-in-time copy  320  may be a logical point-in-time copy  320  meaning that no (or very little) actual data may be copied at the time the point-in-time copy  320  is created. Rather, the point-in-time copy  320  may consist of the production data  318  (for data that has not changed) as well as a side file  302  that keeps track of changes to the production data  318  after the point-in-time copy  320  is created. All or part of the side file  302  may, in certain embodiments, be stored in cache  300  of the storage system  110   e.    
         [0039]    During creation of the point-in-time copy  320 , the production data  318  may be serialized (i.e., locked). Since no data needs to be copied, this lock may be very brief (e.g., on the order of seconds), thereby freeing up the production data  318  for access by other applications. Once the point-in-time copy  320  is created, the update module  306  may keep track of changes to the production data  318  by writing to the side file  302 . For example, if, after creation of the point-in-time copy  320 , data is written to tracks of the production data  318 , the update module  306  may store the previous version of the tracks in the side file  302 , thereby retaining the state of the production data  318  at the time of the point-in-time copy  320 . 
         [0040]    The backup request module  326  on the host system  106  may generate a request to back up a point-in-time copy  320  on the storage system  110   e  to the backup storage system  110   f . To make such a request, the copy identification module  328  may identify the point-in-time copy  320  to be backed up by specifying the identifier previously discussed. The portion identification module  330  may identify specific portions of the point-in-time copy  320  to back up. For example, the portion identification module  330  may identify specific tracks or other storage or data elements to be backed up in the point-in-time copy  320 . This allows specific portions to be backed up as opposed to the entire point-in-time copy  320 , although the entire point-in-time copy  320  may also be backed up, if desired. The backup request may then be transmitted to the storage system  110   e  along with the identifier associated with the point-in-time copy  320  and specific portions within the point-in-time copy  320 . In certain embodiments, the backup request module  326  may also provide, to the storage system  110   e , a cloud name, container name, and/or object name that data should be stored under in a cloud object store. 
         [0041]    The backup module  308  may then back up the point-in-time copy  320  in accordance with the received request. That is, the backup module  308  may copy the specific portions of the point-in-time copy  320  to the backup storage system  110   f  to create a backup copy  334 . As shown in  FIG. 3 , this backup storage system  110   f  may, in certain embodiments, be located in the cloud  332 . That is, the backup storage system  110   f  may provided as a service over a network such as the Internet to store the production data  318 , or portions thereof, as objects or blocks. Because the backup module  308  is located within the storage system  110   e , once the backup request is received, the storage system  110   e  may be configured to perform the backup with little or no host involvement. That is, the backup module  308  may directly copy the point-in-time copy  320 , or portions thereof, to the backup storage system  110   f  with little or no involvement of the host system  106 . This reduces stress and/or overhead on the host system  106 . 
         [0042]    To back up the point-in-time copy  320 , the backup module  308  may include one or more sub-modules  310 ,  312 ,  314 ,  316 . These sub-modules may include one or more of a determination module  310 , search module  312 , read module  314 , and write module  316 . When a backup request is received from the host system  106 , the determination module  310  may determine which point-in-time copy  320  to back up (using the identifier previously discussed) as well as the specific portions in the point-in-time copy  320  to back up. The search module  312  may then search for the point-in-time copy  320  and the specific portions to back up. Once the point-in-time copy  320  is located, the search module  312  may initially search the production data  318  for tracks (or other storage elements) identified in the request. Tracks that have not been updated since creation of the point-in-time copy  320  may be found in the production data  318 . Tracks that have been updated since creation of the point-in-time copy  320  may be found in the side file  302 . 
         [0043]    In certain embodiments, tracks (or other storage elements) in the side file  302  may not be stored in the same order in which they are found in the production data  318  since the tracks may be written to the side file  302  in the order in which they are updated. Thus, the search module  312  may need to search through the side file  302  to find the tracks identified for back up. When tracks identified for back up are located in the production data  318  and/or side file  302 , the read module  314  may read the tracks and the write module  316  may write the tracks to the backup copy  334  on the backup storage system  110   f . Although tracks stored in the side file  302  may not be in the same order as the production data  318 , these tracks may nevertheless need to be written to the cloud  332  in order. Thus, in certain embodiments, tracks are searched for in order and/or sorted and written to the backup storage system  110   f  in order. 
         [0044]    Referring generally to  FIGS. 4 through 7 , interaction between the host system  106 , storage system  110   e , and backup storage system  110   f  when backing up production data  318 , is illustrated. As shown in  FIG. 4 , a host system  106  may initially transmit a request  400  to create a point-in-time copy  320  to the storage system  110   e . As shown, the host system  106  generates a point-in-time copy session ID  402  (an example of an identifier) and transmits this session ID  402  to the storage system  110   e  either with the request  400  or as a separate message. Alternatively, the storage system  110   e  may generate the session ID  402  to assign to the point-in-time copy  320  and return this ID to the host system  106 . In response to the request  400 , the storage system  110   e  creates a logical point-in-time copy  320  of production data  318  residing on the storage system  110   e  and assigns the session ID  402  to the point-in-time copy  320 . 
         [0045]    As previously mentioned the point-in-time copy  320  may be “logical” in that no or very little data may be actually copied when creating the point-in-time copy  320 . Rather, the point-in-time copy  320  may consist of the production data  318  for data that has not changed, and a side file  302  for production data  318  that has changed since creation of the point-in-time copy  320 . 
         [0046]    Once the point-in-time copy  320  has been created, the storage system  110   e  may return an acknowledgement  500  to the host system  106  that indicates that the point-in-time copy  320  has been successfully created, as shown in  FIG. 5 . This may enable the host system  106  to unlock the production data  318 , thereby allowing immediate access to other applications/systems. 
         [0047]    Once the point-in-time copy  320  is created on the storage system  110   e , the host system  106  may transmit a request  600  to back up the point-in-time copy  320  to the storage system  110   e , as shown in  FIG. 6 . The session ID associated with the point-in-time copy  320  may be provided with the request  600  or sent as a separate message. In certain embodiments, the request  600  or a separate message  602  identifies tracks (or other storage elements) in the point-in-time copy  320  to back up. In certain embodiments, the host system  106  may also provide, to the storage system  110   e , a cloud name, container name, and/or object name that data should be stored under in a cloud object store. 
         [0048]    In response to the request  600 , the backup module  308  in the storage system  110   e  may back up the identified tracks in the point-in-time copy  320 . This may be accomplished by searching for the tracks either in the production data  318  or the side file  302 , reading the tracks, and then writing the tracks to a backup storage system  110   f  to create a backup copy  334 . As shown in  FIG. 7 , once the backup is complete, the storage system  110   e  may return an acknowledgment  700  to the host system  106  indicating that the requested backup is complete. 
         [0049]    The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.