Patent Publication Number: US-9424136-B1

Title: Systems and methods for creating optimized synthetic backup images

Description:
BACKGROUND 
     In today&#39;s world of vast computing technology, many technology users are concerned with protecting the integrity and reliability of their virtual machines. In an effort to address this concern, some users may utilize a backup and restore technology to back up their virtual machines. For example, a conventional backup and restore technology may capture a full backup image of a virtual machine. In this example, the conventional backup and restore technology may later capture an incremental backup image that includes only those data blocks that have changed within the virtual machine since the full backup image. The conventional backup and restore technology may then be able to use the incremental backup image in conjunction with the full backup image to create a synthetic backup image that includes all of the data blocks located within the virtual machine at the later point in time. 
     Unfortunately, while conventional backup and restore technologies may be able to use an incremental backup image in conjunction with a full backup image to create a synthetic backup image, such backup and restore technologies may suffer from one or more shortcomings and/or inefficiencies. For example, a conventional backup and restore technology may be unable to create a synthetic backup image that includes only the data currently used by the virtual machine. In another example, the conventional backup and restore technology may need to mount and index one or more virtual disks of the synthetic backup image in order to complete the synthesis process. 
     As such, the instant disclosure identifies a need for additional and improved systems and methods for creating optimized synthetic backup images. 
     SUMMARY 
     As will be described in greater detail below, the instant disclosure generally relates to systems and methods for creating optimized synthetic backup images based at least in part on a data stream that includes at least one changed data block and at least one reference that identifies where at least one unchanged data block is located within a previous backup image. 
     In one example, a computer-implemented method for creating optimized synthetic backup images may include (1) transferring a backup image that represents a virtual machine at a specific point in time to a server that stores the backup image, (2) identifying a subsequent backup image that represents at least a portion of the virtual machine at a subsequent point in time, (3) creating a data stream that includes (i) at least one data block captured in the subsequent backup image that changed within the virtual machine between the specific point in time and the subsequent point in time and (ii) at least one reference that identifies where at least one data block that remained unchanged within the virtual machine between the specific point in time and the subsequent point in time is located within the backup image stored on the server, and then (4) transferring the data stream to the server to enable the server to (i) create a synthetic backup image that represents the virtual machine at the subsequent point in time based at least in part on the changed data block included in the data stream and the unchanged data block whose location within the backup image is identified by the reference and (ii) optimize the synthetic backup image by excluding at least one data block captured in the backup image that was deleted from the virtual machine between the specific point in time and the subsequent point in time. 
     In some examples, the method may also include identifying a plurality of data blocks included in the backup image of the virtual machine. In such examples, the method may further include creating a file that identifies where the plurality of data blocks are located within the backup image of the virtual machine. 
     In some examples, the method may also include determining where the unchanged data block is located within the backup image based at least in part on the file. In such examples, the method may further include searching the file for the location of the unchanged data block within the backup image of the virtual machine. Additionally or alternatively, the method may include identifying the location of the unchanged data block within the backup image of the virtual machine while searching the file. 
     In some examples, the method may also include mapping a plurality of volumes within the backup image of the virtual machine. In such examples, the method may further include identifying a location of each of the plurality of data blocks within the backup image of the virtual machine while mapping the plurality of volumes. 
     In some examples, the method may also include obtaining a list of changed data blocks from virtualization software that facilitates execution of the virtual machine. In such examples, the method may further include determining that the data block has changed within the virtual machine based at least in part on the list of changed data blocks obtained from the virtualization software. 
     In some examples, the method may also include storing the optimized synthetic backup image to facilitate restoring the virtual machine to a computing state experienced by the virtual machine at the subsequent point in time. In such examples, the method may further include restoring the virtual machine without the data block deleted from the virtual machine between the specific point in time and the subsequent point in time. 
     In some examples, the method may also include capturing the backup image of the virtual machine on a host computing system at the specific point in time. Additionally or alternatively, the method may include obtaining the backup image from the host computing system. 
     In some examples, the method may also include capturing the backup image of the virtual machine on the host computing system at the subsequent point in time. Additionally or alternatively, the method may include obtaining the backup image from the host computing system. 
     In some examples, the backup image may include a full backup of the virtual machine. In such examples, the subsequent backup image may include an incremental backup of the virtual machine. Additionally or alternatively, the reference that identifies where the unchanged data block is located within the backup image may include a placeholder for the unchanged data block. 
     In one embodiment, a system for implementing the above-described method may include (1) a transfer module that transfers a backup image that represents a virtual machine at a specific point in time to a server that stores the backup image, (2) an identification module that identifies a subsequent backup image that represents at least a portion of the virtual machine at a subsequent point in time, (3) a creation module that creates a data stream including (i) at least one data block captured in the subsequent backup image that changed within the virtual machine between the specific point in time and the subsequent point in time and (ii) at least one reference that identifies where at least one data block that remained unchanged within the virtual machine between the specific point in time and the subsequent point in time is located within the backup image stored on the server. The transfer module may further transfer the data stream to the server to enable the server to (1) create a synthetic backup image that represents the virtual machine at the subsequent point in time based at least in part on the changed data block included in the data stream and the unchanged data block whose location within the backup image is identified by the reference and (2) optimize the synthetic backup image by excluding at least one data block captured in the backup image that was deleted from the virtual machine between the specific point in time and the subsequent point in time. The system may also include at least one processor configured to execute the identification module, the transfer module, and the creation module. 
     In some examples, the above-described method may be encoded as computer-readable instructions on a computer-readable-storage medium. For example, a computer-readable-storage medium may include one or more computer-executable instructions that, when executed by at least one processor of a computing device, may cause the computing device to (1) transfer a backup image that represents a virtual machine at a specific point in time to a server that stores the backup image, (2) identify a subsequent backup image that represents at least a portion of the virtual machine at a subsequent point in time, (3) create a data stream that includes (i) at least one data block captured in the subsequent backup image that changed within the virtual machine between the specific point in time and the subsequent point in time and (ii) at least one reference that identifies where at least one data block that remained unchanged within the virtual machine between the specific point in time and the subsequent point in time is located within the backup image stored on the server, and then (4) transfer the data stream to the server to enable the server to (i) create a synthetic backup image that represents the virtual machine at the subsequent point in time based at least in part on the changed data block included in the data stream and the unchanged data block whose location within the backup image is identified by the reference and (ii) optimize the synthetic backup image by excluding at least one data block captured in the backup image that was deleted from the virtual machine between the specific point in time and the subsequent point in time. 
     Features from any of the above-mentioned embodiments may be used in combination with one another in accordance with the general principles described herein. These and other embodiments, features, and advantages will be more fully understood upon reading the following detailed description in conjunction with the accompanying drawings and claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings illustrate a number of exemplary embodiments and are a part of the specification. Together with the following description, these drawings demonstrate and explain various principles of the instant disclosure. 
         FIG. 1  is a block diagram of an exemplary system for creating optimized synthetic backup images. 
         FIG. 2  is a block diagram of an exemplary system for creating optimized synthetic backup images. 
         FIG. 3  is a block diagram of an exemplary system for creating optimized synthetic backup images. 
         FIG. 4  is a flow diagram of an exemplary method for creating optimized synthetic backup images. 
         FIG. 5  is an illustration of an exemplary state file and an exemplary list of changed data blocks. 
         FIG. 6  is an illustration of an exemplary data stream that facilitates synthesizing and optimizing a backup image on a media server. 
         FIG. 7  is a block diagram of an exemplary computing system capable of implementing one or more of the embodiments described and/or illustrated herein. 
         FIG. 8  is a block diagram of an exemplary computing network capable of implementing one or more of the embodiments described and/or illustrated herein. 
     
    
    
     Throughout the drawings, identical reference characters and descriptions indicate similar, but not necessarily identical, elements. While the exemplary embodiments described herein are susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, the exemplary embodiments described herein are not intended to be limited to the particular forms disclosed. Rather, the instant disclosure covers all modifications, equivalents, and alternatives falling within the scope of the appended claims. 
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The present disclosure is generally directed to systems and methods for creating optimized synthetic backup images. As will be explained in greater detail below, by creating a state file that identifies where specific data blocks are located within the full backup image of a virtual machine and then transferring the full backup image to a media server for long-term storage and/or maintenance, the various systems and methods described herein may reference this state file to create a data stream that facilitates synthesizing and optimizing a subsequent backup image of the virtual machine on the media server. 
     For example, by referencing this state file, the various systems and methods described herein may be able to create a data stream that includes (1) at least one data block that has changed within the virtual machine and (2) at least one reference that identifies where at least one data block that has remained unchanged within the virtual machine is located within the full backup image stored on the media server. By creating this data stream and then transferring the same to the media server, the various systems and methods described herein may enable the media server to synthesize and optimize a true accelerated backup image of the virtual machine that excludes data blocks previously deleted from the virtual machine without mounting any virtual disks of the synthetic backup image to complete the synthesis process. 
     The following will provide, with reference to  FIGS. 1-3 , detailed descriptions of exemplary systems for creating optimized synthetic backup images. Detailed descriptions of corresponding computer-implemented methods will be provided in connection with  FIG. 4 . Detailed descriptions of an exemplary state file and data stream will be provided in connection with  FIGS. 5 and 6 , respectively. In addition, detailed descriptions of an exemplary computing system and network architecture capable of implementing one or more of the embodiments described herein will be provided in connection with  FIGS. 7 and 8 , respectively. 
       FIG. 1  is a block diagram of an exemplary system  100  for creating optimized synthetic backup images. As illustrated in this figure, exemplary system  100  may include one or more modules  102  for performing one or more tasks. For example, and as will be explained in greater detail below, exemplary system  100  may include an identification module  104  that identifies (1) a backup image of the virtual machine that represents a virtual machine at a specific point in time, (2) a subsequent backup image that represents at least a portion of the virtual machine at a subsequent point in time, (3) at least one data block captured in the subsequent backup image that changed within the virtual machine between the specific point in time and the subsequent point in time, and/or (4) at least one data block that remained unchanged within the virtual machine between the specific point in time and the subsequent point in time. 
     In addition, and as will be described in greater detail below, exemplary system  100  may also include a creation module  108  that creates a data stream that includes (i) the changed data block captured in the subsequent backup image and (ii) at least one reference that identifies where the unchanged data block is located within the backup image. Exemplary system  100  may also include a transfer module  106  that transfers (1) the backup image of the virtual machine to a server and/or (2) the data stream to the server to enable the server to (i) create a synthetic backup image that represents the virtual machine at the subsequent point in time based at least in part on the changed data block included in the data stream and the unchanged data block whose location within the backup image is identified by the reference and/or (ii) optimize the synthetic backup image by excluding at least one data block captured in the backup image that was deleted from the virtual machine between the specific point in time and the subsequent point in time. 
     In some embodiments, exemplary system  100  may further include a capture module  118  that captures (1) the backup image of the virtual machine at the specific point in time and/or (2) the subsequent backup image of the virtual machine at the subsequent point in time. Although illustrated as separate elements, one or more of modules  102  in  FIG. 1  may represent portions of a single module or application (such as SYMANTEC NETBACKUP, SYMANTEC BACKUP EXEC, SYMANTEC SYSTEM RECOVERY, VMWARE CONSOLIDATED BACKUP, VEEAM BACKUP AND REPLICATION, IBM TRIVOLI STORAGE MANAGER, QUEST VRANGER, or ACRONIS BACKUP &amp; RECOVERY). 
     In certain embodiments, one or more of modules  102  in  FIG. 1  may represent one or more software applications or programs that, when executed by a computing device, may cause the computing device to perform one or more tasks. For example, and as will be described in greater detail below, one or more of modules  102  may represent software modules stored and configured to run on one or more computing devices, such as the devices illustrated in  FIGS. 2 and 3  (e.g., computing device  202  and/or media server  206 ), the devices illustrated in  FIG. 3  (e.g., computing device  302 , media server  306 , and/or backup host  308 ), computing system  710  in  FIG. 7 , and/or portions of exemplary network architecture  800  in  FIG. 8 . One or more of modules  102  in  FIG. 1  may also represent all or portions of one or more special-purpose computers configured to perform one or more tasks. 
     Exemplary system  100  may also include one or more databases (not illustrated in  FIG. 1 ) located on one or more computing devices. In one example, a database may be configured to store any data and/or information used to create optimized synthetic backup images of a virtual machine (such as virtual machine  114  in  FIG. 1 ). The phrase “virtual machine,” as used herein, generally refers to any operating system environment that is abstracted from computing hardware by a virtual machine manager (e.g., a hypervisor). 
     In one example, the database may store one or more of backup images (such as backup images  110  and  112  and/or synthetic backup image  120  in  FIG. 1 ) that represent the virtual machine at specific points in time. The phrase “backup image,” as used herein, generally refers to any type or form of file that includes a complete or partial copy of the contents and/or data located on a computing or storage device at a particular point in time. Examples of such backup images include, without limitation, full backup images, incremental backup images, differential backup images, accelerated backup images, deduplicated backup images, synthetic backup images, snapshots, combinations of one or more of the same, or any other suitable backup images. 
     Additionally or alternatively, the database may store at least one data stream (such as data stream  116  in  FIG. 1 ) that facilitates synthesizing and/or optimizing at least one of the backup images. The phrase “data stream,” as used herein, generally refers to any type or form of bit sequence that is streamed to a computing device (such as media server  206  in  FIG. 2  or media server  306  in  FIG. 3 ) over a period of time. Examples of such a data stream include, without limitation, bitstreams, bytestreams, Tape Archive (TAR) streams, TAR headers, codatas, combinations of one or more of the same, or any other suitable data streams. 
     Additionally or alternatively, the database may store at least one synthetic backup image (such as synthetic backup image  120  in  FIG. 1 ). The phrase “synthetic backup image,” as used herein, generally refers to any type or form of backup image that represents the computing state of a virtual machine at a specific point in time and is synthesized based at least in part on a data stream and/or a previously captured backup image. 
     The database may represent portions of a single database or computing device or a plurality of databases or computing devices. For example, the database may represent one or more portions of computing device  202  and/or media server  206  in  FIG. 2 , computing device  302 , media server  306 , and/or backup host  308  in  FIG. 3 , computing system  710  in  FIG. 7 , and/or portions of exemplary network architecture  800  in  FIG. 8 . Alternatively, the database may represent one or more physically separate devices capable of being accessed by a computing device, such as computing device  202  and/or media server  206  in  FIG. 2 , computing device  302 , media server  306 , and/or backup host  308  in  FIG. 3 , computing system  710  in  FIG. 7 , and/or portions of exemplary network architecture  800  in  FIG. 8 . 
     Exemplary system  100  in  FIG. 1  may be implemented in a variety of ways. For example, all or a portion of exemplary system  100  may represent portions of exemplary system  200  in  FIG. 2 . As shown in  FIG. 2 , system  200  may include a computing device  202  in communication with a media server  206  via a network  204 . Computing device  202  may be programmed with one or more of modules  102  and/or virtual machine  114 . Computing device  202  may also include backup image  112  and/or data stream  116 . 
     Additionally or alternatively, server  206  may be programmed with one or more of modules  102 . Media server  206  may also include backup image  110  and/or synthetic backup image  120 . 
     In another example, all or a portion of exemplary system  100  may represent portions of exemplary system  300  in  FIG. 3 . As shown in  FIG. 3 , system  300  may include a computing device  302  in communication with a backup host  308  and/or a media server  306  via a network  304 . Computing device  302  may be programmed with one or more of modules  102  and/or virtual machine  114 . 
     Additionally or alternatively, media server  306  may be programmed with one or more of modules  102 . Media server  306  may also include backup image  110  and/or synthetic backup image  120 . 
     Additionally or alternatively, backup host  308  may be programmed with one or more of modules  102 . Backup host  308  may also include backup image  112  and/or data stream  116 . 
     In one embodiment, one or more of modules  102  from  FIG. 1  may, when executed by at least one processor of at least one of the devices illustrated in  FIG. 2 or 3 , facilitate the device in creating optimized synthetic backup images. For example, and as will be described in greater detail below, one or more of modules  102  may cause computing device  202  in  FIG. 2  or backup host  308  in  FIG. 3  to (1) identify backup image  110  that represents virtual machine  114  at a specific point in time, (2) transfer backup image  110  of virtual machine  114  to a media server (e.g., media server  206  in  FIG. 2  or media server  306  in  FIG. 3 ), (3) identify backup image  112  that represents at least a portion of virtual machine  114  at a subsequent point in time, (4) identify at least one data block captured in backup image  112  that changed within virtual machine  114  between the specific point in time and the subsequent point in time, (5) identify at least one data block that remained unchanged within virtual machine  114  between the specific point in time and the subsequent point in time, (6) create data stream  116  that includes (i) the changed data block captured in backup image  112  and (ii) at least one reference that identifies where the unchanged data block is located within backup image  110 , and then (7) transfer data stream  116  to the media server to enable the media server to (i) create synthetic backup image  120  that represents virtual machine  114  at the subsequent point in time based at least in part on the changed data block included in data stream  116  and the unchanged data block whose location within backup image  110  is identified by the reference and (ii) optimize synthetic backup image  120  by excluding at least one data block captured in backup image  110  that was deleted from virtual machine  114  between the specific point in time and the subsequent point in time. 
     Computing devices  202  and  302  generally represent any type or form of computing device capable of reading computer-executable instructions. Examples of computing devices  202  and  302  include, without limitation, laptops, tablets, desktops, servers, cellular phones, Personal Digital Assistants (PDAs), multimedia players, embedded systems, combinations of one or more of the same, exemplary computing system  710  in  FIG. 7 , or any other suitable computing device. 
     Media servers  206  and  306  generally represent any type or form of computing device capable of storing, maintaining, providing, and/or synthesizing backup images of a virtual machine. Examples of media servers  206  and  306  include, without limitation, application servers, web servers, storage servers, deduplication servers, and/or database servers configured to run certain software applications and/or provide various web, storage, and/or database services. 
     Backup host  308  generally represents any type or form of computing device capable of creating data streams that facilitate synthesizing and/or optimizing backup images on media servers. Examples of backup host  308  include, without limitation, laptops, tablets, desktops, servers, cellular phones, Personal Digital Assistants (PDAs), multimedia players, embedded systems, combinations of one or more of the same, exemplary computing system  710  in  FIG. 7 , or any other suitable backup host  308 . 
     Networks  204  and  304  generally represents any medium or architecture capable of facilitating communication or data transfer. Examples of networks  204  and  304  include, without limitation, an intranet, a Wide Area Network (WAN), a Local Area Network (LAN), a Personal Area Network (PAN), the Internet, Power Line Communications (PLC), a cellular network (e.g., a Global System for Mobile Communications (GSM) network), exemplary network architecture  800  in  FIG. 8 , or the like. Networks  204  and  304  may facilitate communication or data transfer using wireless or wired connections. 
       FIG. 4  is a flow diagram of an exemplary computer-implemented method  400  for creating optimized synthetic backup images. The steps shown in  FIG. 4  may be performed by any suitable computer-executable code and/or computing system. In some embodiments, the steps shown in  FIG. 4  may be performed by one or more of the components of system  100  in  FIG. 1 , system  200  in  FIG. 2 , system  300  in  FIG. 3 , computing system  710  in  FIG. 7 , and/or portions of exemplary network architecture  800  in  FIG. 8 . 
     As illustrated in  FIG. 4 , at step  402  one or more of the systems described herein may identify a backup image that represents a virtual machine at a specific point in time. For example, at step  402  identification module  104  may, as part of computing device  202  in  FIG. 2  or backup host  308  in  FIG. 3 , identify backup image  110  that represents virtual machine  114  at a specific point in time. In one example, backup image  110  may include a full backup image of virtual machine  114 . In another example, backup image  110  may include an incremental backup image of virtual machine  114  used to synthesize a full backup image. 
     The systems described herein may perform step  402  in a variety of ways. In some examples, identification module  104  may identify backup image  110  of virtual machine  114  as backup image  110  is captured. For example, capture module  118  may, as part of computing device  202  in  FIG. 2 , capture backup image  110  of virtual machine  114  on computing device  202  at the specific point in time. In this example, as capture module  118  captures backup image  110  of virtual machine  114 , identification module  104  may identify backup image  110 . 
     Upon identifying backup image  110 , identification module  104  may identify a plurality of data blocks included in backup image  110 . For example, identification module  104  may map a plurality of volumes within backup image  110 . In this example, while mapping the plurality of volumes within backup image  110 , identification module  104  may identify a location of each of the plurality of data blocks within backup image  110 . 
     After identification module  104  has identified the location of each of the plurality of data blocks within backup image  110 , creation module  108  may, as part of computing device  202  in  FIG. 2 , create a state file  500  that identifies where the plurality of data blocks are located within backup image  110 . As illustrated in  FIG. 5 , state file  500  may include information that identifies a plurality of data blocks captured in backup image  110  (in this example, “FOO.EXE,” “BAR.EXE,” and so on) as well as the respective locations of the plurality of data blocks within backup image  110  (in this example, “0x10A7D8C0,” “0x45F5E100,” and so on). 
     In some examples, identification module  104  may identify backup image  110  of virtual machine  114  after backup image  110  is captured. For example, capture module  118  may, as part of computing device  302  in  FIG. 3 , capture backup image  110  of virtual machine  114  on computing device  302  at the specific point in time. After capture module  118  has captured backup image  110  of virtual machine  114 , transfer module  106  may, as part of computing device  302  in  FIG. 3 , direct computing device  302  to transfer backup image  110  to backup host  308  via network  304 . 
     Continuing with this example, backup host  308  may receive backup image  110  from computing device  302  via network  304 . As backup host  308  receives backup image  110 , identification module  104  may, as part of backup host  308  in  FIG. 3 , obtain and identify backup image  110 . Upon identifying backup image  110 , identification module  104  may identify a plurality of data blocks included in backup image  110 . Creation module  108  may then, as part of backup host  308  in  FIG. 3 , create state file  500  that identifies where the plurality of data blocks are located within backup image  110 . 
     As illustrated in  FIG. 4 , at step  404  one or more of the systems described herein may transfer the backup image of the virtual machine to a server that stores the backup image. For example, at step  404  transfer module  106  may, as part of computing device  202  in  FIG. 2  or backup host  308  in  FIG. 3 , transfer backup image  110  of virtual machine  114  to a media server for storage and/or maintenance. In this example, by transferring backup image  110  of virtual machine  114  to the media server, transfer module  106  may provide the media server with a baseline for synthesizing a true accelerated backup image of virtual machine  114 . 
     The systems described herein may perform step  404  in a variety of ways. In some examples, transfer module  106  may direct computing device  202  to transfer backup image  110  of virtual machine  114  to media server  206  via network  204 . In such examples, media server  206  may receive backup image  110  from computing device  202  via network  204 . Upon receiving backup image  110  from computing device  202 , media server  206  may store and/or maintain backup image  110  to facilitate synthesizing a true accelerated backup image of virtual machine  114 . 
     In some examples, transfer module  106  may direct backup host  308  to transfer backup image  110  of virtual machine  114  to media server  306  via network  304 . In such examples, media server  306  may receive backup image  110  from backup host  308  via network  304 . Upon receiving backup image  110  from backup host  308 , media server  306  may store and/or maintain backup image  110  to facilitate synthesizing a true accelerated backup image of virtual machine  114 . 
     As illustrated in  FIG. 4 , at step  406  one or more of the systems described herein may identify a subsequent backup image that represents at least a portion of the virtual machine at a subsequent point in time. For example, at step  406  identification module  104  may, as part of computing device  202  in  FIG. 2  or backup host  308  in  FIG. 3 , identify backup image  112  that represents at least a portion of virtual machine  114  at a subsequent point in time. In one example, backup image  112  may include a full backup image of virtual machine  114 . In another example, backup image  112  may include an incremental backup image of virtual machine  114  used to synthesize a true accelerated backup image of virtual machine  114 . 
     The systems described herein may perform step  406  in a variety of ways. In some examples, identification module  104  may identify backup image  112  of virtual machine  114  as backup image  112  is captured. For example, capture module  118  may, as part of computing device  202  in  FIG. 2 , capture backup image  112  of virtual machine  114  on computing device  202  at the subsequent point in time. In this example, as capture module  118  captures backup image  112  of virtual machine  114 , identification module  104  may identify backup image  112 . 
     Upon identifying backup image  112 , identification module  104  may identify a plurality of data blocks included in backup image  112 . For example, identification module  104  may map a plurality of volumes within backup image  112 . In this example, while mapping the plurality of volumes within backup image  112 , identification module  104  may identify a location of each of the plurality of data blocks within backup image  112 . 
     After identification module  104  has identified the location of each of the plurality of data blocks within backup image  112 , creation module  108  may, as part of computing device  202  in  FIG. 2 , create a subsequent state file (not illustrated in  FIG. 5 ) that identifies where the plurality of data blocks are located within backup image  112 . In one example, creation module  108  may retrieve state file  500  to use as a baseline for creating the subsequent state file that identifies where the plurality of data blocks are located within backup image  112  (by, e.g., modifying state file  500 ). In another example, creation module  108  may create the subsequent state file that identifies where the plurality of data blocks are located within backup image  112  without using any previous state file as a baseline. 
     In some examples, identification module  104  may identify backup image  112  of virtual machine  114  after backup image  110  is captured. For example, capture module  118  may, as part of computing device  302  in  FIG. 3 , capture backup image  112  of virtual machine  114  on computing device  302  at the subsequent point in time. After capture module  118  has captured backup image  112  of virtual machine  114 , transfer module  106  may, as part of computing device  302  in  FIG. 3 , direct computing device  302  to transfer backup image  112  to backup host  308  via network  304 . 
     Continuing with this example, backup host  308  may receive backup image  112  from computing device  302  via network  304 . As backup host  308  receives backup image  112 , identification module  104  may, as part of backup host  308  in  FIG. 3 , obtain and identify backup image  112 . Upon identifying backup image  112 , identification module  104  may identify a plurality of data blocks included in backup image  112 . Creation module  108  may then, as part of backup host  308  in  FIG. 3 , create a subsequent state file that identifies where the plurality of data blocks are located within backup image  112 . 
     As illustrated in  FIG. 4 , at step  408  one or more of the systems described herein may identify at least one data block captured in the subsequent backup image that changed within the virtual machine between the specific point in time and the subsequent point in time. For example, at step  408  identification module  104  may, as part of computing device  202  in  FIG. 2  or backup host  308  in  FIG. 3 , identify at least one data block captured in backup image  112  that changed within virtual machine  114  between the specific point in time and the subsequent point in time. In one example, the changed data block may include a new file that did not exist within virtual machine  114  at the specific point in time but did exist within virtual machine  114  at the subsequent point in time. In another example, the changed data block may include at least a portion of a file that was modified or deleted within virtual machine  114  between the specific point in time and the subsequent point in time. 
     The systems described herein may perform step  408  in a variety of ways. In some examples, identification module  104  may obtain a list of changed data blocks from virtualization software that facilitates execution of the virtual machine  114 . For example, computing device  202  may include a VMWARE virtualization environment that facilitates execution of virtual machine  114 . In this example, the VMWARE virtualization environment may have a Changed Block Tracking (CBT) feature that tracks any changes to data blocks within virtual machine  114 . The VMWARE virtualization environment may use the CBT feature to create a list  502  of data blocks that have changed within virtual machine  114  between the specific point in time and the subsequent point in time. 
     As illustrated in  FIG. 5 , list  502  may include information that identifies a plurality of data blocks that changed within virtual machine  114  between the specific point in time and the subsequent point in time (in this example, “FILE.EXE,” and so on) as well as the respective locations of the plurality of changed data blocks within backup image  112  (in this example, “0x2084829A,” and so on). 
     Identification module  104  may request list  502  from the VMWARE virtualization environment upon identifying backup image  112 . In response to this request, the VMWARE virtualization environment may provide list  502  to identification module  104 . Identification module  104  may obtain list  502  from the VMWARE virtualization environment. 
     Upon obtaining list  502  from the VMWARE virtualization environment, identification module  104  may analyze list  502  to identify any data blocks that changed within virtual machine  114  between the specific point in time and the subsequent point in time. For example, identification module  104  may analyze list  502  and determine that data block “FILE.EXE” changed within virtual machine  114  between the specific point in time and the subsequent point in time based at least in part on the analysis. In this example, identification module  104  may then determine that changed data block “FILE.EXE” is located at address “0x2084829A” based at least in part on list  502 . 
     As illustrated in  FIG. 4 , at step  410  one or more of the systems described herein may identify at least one data block that remained unchanged within the virtual machine between the specific point in time and the subsequent point in time. For example, at step  410  identification module  104  may, as part of computing device  202  in  FIG. 2  or backup host  308  in  FIG. 3 , identify at least one data block that remained unchanged within virtual machine  114  between the specific point in time and the subsequent point in time. In this example, the unchanged data block may include at least a portion of a file that was neither modified nor deleted within virtual machine  114  between the specific point in time and the subsequent point in time. 
     The systems described herein may perform step  410  in a variety of ways. In some examples, identification module  104  may deduce the unchanged block&#39;s identity based at least in part on state file  500  and/or list  502 . In one example, identification module  104  may compare state file  500  and list  502 . For example, identification module  104  may identify data block “FOO.EXE” located at address “0x10A7D8C0” and data block “BAR.EXE” located at address “0x45F5E100” in state file  500 . In this example, identification module  104  may search list  502  for data blocks “FOO.EXE” and “BAR.EXE” and fail to find these data blocks during the search of list  502 . Identification module  104  may then determine that data blocks “FOO.EXE” and “BAR.EXE” remained unchanged within virtual machine  114  between the specific point in time and the subsequent point in time since these data blocks were not found in list  502 . 
     In some examples, upon deducing the unchanged block&#39;s identity, identification module  104  may determine where the unchanged data block is located within the backup image based at least in part on state file  500 . For example, identification module  104  may search state file  500  for the respective locations of data blocks “FOO.EXE” and “BAR.EXE” within backup image  110  stored on media server  206 . In this example, while searching state file  500 , identification module  104  may identify address “0x10A7D8C0” as the location of data block “FOO.EXE” and address “0x45F5E100” as the location of data block “BAR.EXE” within backup image  110 . 
     As illustrated in  FIG. 4 , at step  412  one or more of the systems described herein may create a data stream that includes the changed data block and at least one reference that identifies where the unchanged data block is located within the backup image stored on the server. For example, at step  412  creation module  108  may, as part of computing device  202  in  FIG. 2  or backup host  308  in  FIG. 3 , create data stream  116  that includes the changed data block and at least one reference that identifies where the unchanged data block is located within backup image  110  stored on the media server. Examples of data stream  116  include, without limitation, bitstreams, bytestreams, TAR streams, TAR headers, codata, combinations of one or more of the same, or any other suitable data streams. 
     The term “reference,” as used herein, generally refers to any type or form of identifier that identifies or otherwise indicates a location of a specific data block within a backup image. Examples of such a reference include, without limitation, addresses, pointers, hashes, combinations of one or more of the same, or any other type of suitable reference. 
     The systems described herein may perform step  412  in a variety of ways. In some examples, creation module  108  may format data stream  116  in a file format that gives data stream  116  the appearance of a full backup image. As illustrated in  FIG. 6 , data stream  116  may include a sequence of data that resembles a full backup image of virtual machine  114  and includes the changed data blocks (in this example, data block “FILE.EXE” located at address “0x2084829A,” and so on) and the references that identify where the unchanged data blocks are located within backup image  110  stored on the media server (in this example, “REFERENCE TO DATA BLOCK LOCATED AT 0x10A7D8C0 WITHIN BACKUP IMAGE,” “REFERENCE TO DATA BLOCK LOCATED AT 0x45F5E100 WITHIN BACKUP IMAGE,” and so on). 
     In one example, creation module  108  may create data stream  116  by building upon backup image  112  of virtual machine  114 . For example, creation module  108  may create references that identify data blocks “FOO.EXE” and “BAR.EXE” and then add the same to backup image  112 . In this example, creation module  108  may arrange the references in the proper order with respect to data block “FILE.EXE” within backup image  112  such that the references act as placeholders for data blocks “FOO.EXE” and “BAR.EXE” within data stream  116 . By arranging the references in the proper order with respect to data block “FILE.EXE” within backup image  112 , creation module  108  may essentially convert backup image  112  into data stream  116 . 
     In another example, creation module  108  may create data stream  116  by retrieving the changed data block from backup image  112  of virtual machine  114 . For example, creation module  108  may use the references that identify data blocks “FOO.EXE” and “BAR.EXE” as the baseline for creating data stream  116 . In this example, creation module  108  may retrieve data block “FILE.EXE” from backup image  112  and then add the same to data stream  116 . Creation module  108  may arrange the references in the proper order with respect to data block “FILE.EXE” within data stream  116  such that the references act as placeholders for data blocks “FOO.EXE” and “BAR.EXE.” 
     By arranging the references in the proper order with respect to the changed data blocks, creation module  108  may essentially index data stream  116  as though data stream  116  were a full backup image. Since, in this example, creation module  108  has indexed data stream  116  as though data stream  116  were a full backup image, the media server may use data stream  116  to synthesize a true accelerated backup image that represents virtual machine  114  at the subsequent point in time without mounting any virtual disks of the true accelerated synthetic backup image. 
     In other words, since, in this example, creation module  108  has indexed data stream  116  at computing device  202  in  FIG. 2  or backup host  308  in  FIG. 3 , the media server may no longer need to index the synthetic backup image. Moreover, since the media server no longer needs to index the synthetic backup image, the media server may no longer need to mount any of the virtual disks of the synthetic backup image to perform any post-processing and/or indexing operations on the synthetic backup image. 
     As a result, the media server may be able to provide synthesizing and backup services to a variety of different physical and/or virtual computing platforms. In other words, since the media server no longer needs to perform any post-processing and/or indexing operations on the synthetic backup image, the synthesizing and backup services provided by the media server may be platform-independent. 
     In some examples, creation module  108  may exclude each data block that was deleted from virtual machine  114  between the specific point in time and the subsequent point in time from data stream  116 . In one example, identification module  104  may identify each data block that was deleted from virtual machine  114  between the specific point in time and the subsequent point in time. For example, identification module  104  may determine that at least one data block was deleted from virtual machine  114  between the specific point in time and the subsequent point in time by analyzing backup image  112 , state file  500 , and/or list  502 . In this example, since identification module  104  has determined that the data block was deleted from virtual machine  114 , creation module  108  may exclude the data block (as well as any reference to the location of the data block within backup image  110 ) from data stream  116  to enable the media server to optimize the synthetic backup image. 
     As illustrated in  FIG. 4 , at step  414  one or more of the systems described herein may transfer the data stream to the server to enable the server to create and optimize a synthetic backup image that represents the virtual machine at the subsequent point in time. For example, at step  414  transfer module  106  may, as part of computing device  202  in  FIG. 2  or backup host  308  in  FIG. 3 , transfer data stream  116  to the media server. By transferring data stream  116  to the media server, transfer module  106  may enable the media server to create and optimize synthetic backup image  120  that represents virtual machine  114  at the subsequent point in time. 
     The systems described herein may perform step  414  in a variety of ways. In some examples, transfer module  106  may direct computing device  202  to transfer data stream  116  to media server  206  via network  204 . In such examples, media server  206  may receive data stream  116  from computing device  202  via network  204 . Upon receiving data stream  116  from computing device  202 , media server  306  may begin to create synthetic backup image  120  based at least on in part on data stream  116  and backup image  110 . 
     In other examples, transfer module  106  may direct backup host  308  to transfer data stream  116  of virtual machine  114  to media server  306  via network  304 . In such examples, media server  306  may receive backup image  110  from backup host  308  via network  304 . Upon receiving backup image  110  from backup host  308 , media server  306  may begin to synthesize backup image  120  based at least on in part on data stream  116  and backup image  110 . 
     In one example, the media server may create synthetic backup image  120  by replacing the references included in data stream  116  with the data blocks identified by the references. For example, creation module  108  may, as part of media server  206  in  FIG. 2  or media server  306  in  FIG. 3 , search data stream  116  and then find the references to addresses “0x10A7D8C0” and “0x45F5E100” within backup image  110  during this search of data stream  116 . Upon finding these references, creation module  108  may access addresses “0x10A7D8C0” and “0x45F5E100” within backup image  110  and then retrieve data blocks “FOO.EXE” and “BAR.EXE” at the addresses. Creation module  108  may then replace the references to addresses “0x10A7D8C0” and “0x45F5E100” within backup image  110  with data blocks “FOO.EXE” and “BAR.EXE.” 
     By creating synthetic backup image  120  in this manner at media server  206  in  FIG. 2  or media server  306  in  FIG. 3 , creation module  108  may optimize synthetic backup image  120 . For example, since data stream  116  excludes each deleted data block (as well as any reference to a deleted data block&#39;s location within backup image  110 ), creation module  108  may have no reason to add any deleted data blocks to synthetic backup image  120 . As a result, creation module  108  may optimize synthetic backup image  120  by excluding each data block that was deleted from virtual machine  114  between the specific point in time and the subsequent point in time. The term “optimize,” as used herein, generally refers to the act of including only those data blocks used by a virtual machine at a specific point in time in a synthesized backup image that represents the virtual machine at the specific point in time. 
     After creation module  108  has optimized synthetic backup image  120 , the media server may store and/or maintain optimized synthetic backup  120  to enable the media server to facilitate restoring virtual machine  114  to the computing state experienced by virtual machine  114  at the subsequent point in time. For example, the media server may enable computing device  202  in  FIG. 2  or computing device  302  in  FIG. 3  to return virtual machine  114  to the computing state experienced by virtual machine  114  at the subsequent point in time by applying synthetic backup image  120 . In this example, the computing state experienced by virtual machine  114  does not include any of the data blocks that were deleted from virtual machine  114  between the specific point in time and the subsequent point in time. 
     As explained above in connection with method  400  in  FIG. 4 , a backup and restore agent installed on a host computing device may capture a full backup of a virtual machine configured to run on the host computing device. Upon capturing the full backup of the virtual machine, the backup and restore agent may map the volumes within the full backup to identify the location of each data block within the full backup. The backup and restore agent may then create a state file that identifies the location of each data block within the full backup based at least in part on this mapping. 
     Upon creating the state file, the backup and restore agent may direct the host computing device to upload the full backup to the media server via a network. The media server may store and/or maintain the full backup to facilitate synthesizing a backup of the virtual machine at a later point in time. 
     The backup and restore agent installed on the host computing device may later capture a subsequent backup of the virtual machine configured to run on the host computing device. Upon capturing the subsequent backup of the virtual machine, the backup and restore agent may check whether a previous backup of the virtual machine was mapped and uploaded to the media server. During this check, the backup and restore agent may find the state file and then retrieve the same. 
     In addition, the backup and restore agent may obtain a list of changed data blocks from virtualization software installed that facilitates execution of the virtual machine on the host computing device. Upon obtaining the list of changed data blocks, the backup and restore agent may identify each changed data block by analyzing the list. The backup and restore agent may then identify the location of each changed data block within the full backup by analyzing the state file. 
     Upon identifying the location of each changed data block, the backup and restore agent may create a data stream that includes (1) each changed data block as captured in the subsequent backup and (2) one or more references that identify the location of each unchanged data block within the full backup stored on the media server. The backup and restore agent may arrange each reference in the proper order with respect to each changed data block within the data stream such that the references act as placeholders for the unchanged data blocks included in the full backup stored on the media server. By arranging each reference in the proper order with respect to each changed data block within the data stream, the backup and restore agent may essentially index the data stream like a full backup—except that the data stream includes references to the unchanged data blocks rather than including the unchanged data blocks themselves. 
     Upon arranging each reference in the proper order with respect to each changed data block within the data stream, the backup and restore agent may direct the host computing device to upload the full backup to the media server via the network. The media server may create a true accelerated synthetic full backup that represents the virtual machine at the later point in time based at least in part on the data stream and the previous full backup. The media server may then optimize the true accelerated synthetic full backup to exclude each data block deleted from the virtual machine after the capture of the previous full backup. 
     Since the backup and restore agent has indexed the data stream like a full backup, the media server may not need to index the true accelerated synthetic full backup. Moreover, since the media server does not need to index the true accelerated synthetic full backup, the media server may not need to mount any of the virtual disks of the true accelerated synthetic full backup to perform any post-processing and/or indexing operations on the true accelerated synthetic backup. 
     As a result, the media server may be able to provide synthesizing and backup services to a variety of different physical and/or virtual computing platforms. In other words, since the media server does not need to perform any post-processing and/or indexing operations on the true accelerated full synthetic backup, the synthesizing and backup services provided by the media server may be platform-independent. 
       FIG. 7  is a block diagram of an exemplary computing system  710  capable of implementing one or more of the embodiments described and/or illustrated herein. For example, all or a portion of computing system  710  may perform and/or be a means for performing, either alone or in combination with other elements, one or more of the steps described herein (such as one or more of the steps illustrated in  FIG. 4 ). All or a portion of computing system  710  may also perform and/or be a means for performing any other steps, methods, or processes described and/or illustrated herein. 
     Computing system  710  broadly represents any single or multi-processor computing device or system capable of executing computer-readable instructions. Examples of computing system  710  include, without limitation, workstations, laptops, client-side terminals, servers, distributed computing systems, handheld devices, or any other computing system or device. In its most basic configuration, computing system  710  may include at least one processor  714  and a system memory  716 . 
     Processor  714  generally represents any type or form of processing unit capable of processing data or interpreting and executing instructions. In certain embodiments, processor  714  may receive instructions from a software application or module. These instructions may cause processor  714  to perform the functions of one or more of the exemplary embodiments described and/or illustrated herein. 
     System memory  716  generally represents any type or form of volatile or non-volatile storage device or medium capable of storing data and/or other computer-readable instructions. Examples of system memory  716  include, without limitation, Random Access Memory (RAM), Read Only Memory (ROM), flash memory, or any other suitable memory device. Although not required, in certain embodiments computing system  710  may include both a volatile memory unit (such as, for example, system memory  716 ) and a non-volatile storage device (such as, for example, primary storage device  732 , as described in detail below). In one example, one or more of modules  102  from  FIG. 1  may be loaded into system memory  716 . 
     In certain embodiments, exemplary computing system  710  may also include one or more components or elements in addition to processor  714  and system memory  716 . For example, as illustrated in  FIG. 7 , computing system  710  may include a memory controller  718 , an Input/Output (I/O) controller  720 , and a communication interface  722 , each of which may be interconnected via a communication infrastructure  712 . Communication infrastructure  712  generally represents any type or form of infrastructure capable of facilitating communication between one or more components of a computing device. Examples of communication infrastructure  712  include, without limitation, a communication bus (such as an Industry Standard Architecture (ISA), Peripheral Component Interconnect (PCI), PCI Express (PCIe), or similar bus) and a network. 
     Memory controller  718  generally represents any type or form of device capable of handling memory or data or controlling communication between one or more components of computing system  710 . For example, in certain embodiments memory controller  718  may control communication between processor  714 , system memory  716 , and I/O controller  720  via communication infrastructure  712 . 
     I/O controller  720  generally represents any type or form of module capable of coordinating and/or controlling the input and output functions of a computing device. For example, in certain embodiments I/O controller  720  may control or facilitate transfer of data between one or more elements of computing system  710 , such as processor  714 , system memory  716 , communication interface  722 , display adapter  726 , input interface  730 , and storage interface  734 . 
     Communication interface  722  broadly represents any type or form of communication device or adapter capable of facilitating communication between exemplary computing system  710  and one or more additional devices. For example, in certain embodiments communication interface  722  may facilitate communication between computing system  710  and a private or public network including additional computing systems. Examples of communication interface  722  include, without limitation, a wired network interface (such as a network interface card), a wireless network interface (such as a wireless network interface card), a modem, and any other suitable interface. In at least one embodiment, communication interface  722  may provide a direct connection to a remote server via a direct link to a network, such as the Internet. Communication interface  722  may also indirectly provide such a connection through, for example, a local area network (such as an Ethernet network), a personal area network, a telephone or cable network, a cellular telephone connection, a satellite data connection, or any other suitable connection. 
     In certain embodiments, communication interface  722  may also represent a host adapter configured to facilitate communication between computing system  710  and one or more additional network or storage devices via an external bus or communications channel. Examples of host adapters include, without limitation, Small Computer System Interface (SCSI) host adapters, Universal Serial Bus (USB) host adapters, Institute of Electrical and Electronics Engineers (IEEE) 1394 host adapters, Advanced Technology Attachment (ATA), Parallel ATA (PATA), Serial ATA (SATA), and External SATA (eSATA) host adapters, Fibre Channel interface adapters, Ethernet adapters, or the like. Communication interface  722  may also allow computing system  710  to engage in distributed or remote computing. For example, communication interface  722  may receive instructions from a remote device or send instructions to a remote device for execution. 
     As illustrated in  FIG. 7 , computing system  710  may also include at least one display device  724  coupled to communication infrastructure  712  via a display adapter  726 . Display device  724  generally represents any type or form of device capable of visually displaying information forwarded by display adapter  726 . Similarly, display adapter  726  generally represents any type or form of device configured to forward graphics, text, and other data from communication infrastructure  712  (or from a frame buffer, as known in the art) for display on display device  724 . 
     As illustrated in  FIG. 7 , exemplary computing system  710  may also include at least one input device  728  coupled to communication infrastructure  712  via an input interface  730 . Input device  728  generally represents any type or form of input device capable of providing input, either computer or human generated, to exemplary computing system  710 . Examples of input device  728  include, without limitation, a keyboard, a pointing device, a speech recognition device, or any other input device. 
     As illustrated in  FIG. 7 , exemplary computing system  710  may also include a primary storage device  732  and a backup storage device  733  coupled to communication infrastructure  712  via a storage interface  734 . Storage devices  732  and  733  generally represent any type or form of storage device or medium capable of storing data and/or other computer-readable instructions. For example, storage devices  732  and  733  may be a magnetic disk drive (e.g., a so-called hard drive), a solid state drive, a floppy disk drive, a magnetic tape drive, an optical disk drive, a flash drive, or the like. Storage interface  734  generally represents any type or form of interface or device for transferring data between storage devices  732  and  733  and other components of computing system  710 . 
     In certain embodiments, storage devices  732  and  733  may be configured to read from and/or write to a removable storage unit configured to store computer software, data, or other computer-readable information. Examples of suitable removable storage units include, without limitation, a floppy disk, a magnetic tape, an optical disk, a flash memory device, or the like. Storage devices  732  and  733  may also include other similar structures or devices for allowing computer software, data, or other computer-readable instructions to be loaded into computing system  710 . For example, storage devices  732  and  733  may be configured to read and write software, data, or other computer-readable information. Storage devices  732  and  733  may also be a part of computing system  710  or may be a separate device accessed through other interface systems. 
     Many other devices or subsystems may be connected to computing system  710 . Conversely, all of the components and devices illustrated in  FIG. 7  need not be present to practice the embodiments described and/or illustrated herein. The devices and subsystems referenced above may also be interconnected in different ways from that shown in  FIG. 7 . Computing system  710  may also employ any number of software, firmware, and/or hardware configurations. For example, one or more of the exemplary embodiments disclosed herein may be encoded as a computer program (also referred to as computer software, software applications, computer-readable instructions, or computer control logic) on a computer-readable-storage medium. The phrase “computer-readable-storage medium” generally refers to any form of device, carrier, or medium capable of storing or carrying computer-readable instructions. Examples of computer-readable-storage media include, without limitation, transmission-type media, such as carrier waves, and non-transitory-type media, such as magnetic-storage media (e.g., hard disk drives and floppy disks), optical-storage media (e.g., Compact Disks (CDs) or Digital Video Disks (DVDs)), electronic-storage media (e.g., solid-state drives and flash media), and other distribution systems. 
     The computer-readable-storage medium containing the computer program may be loaded into computing system  710 . All or a portion of the computer program stored on the computer-readable-storage medium may then be stored in system memory  716  and/or various portions of storage devices  732  and  733 . When executed by processor  714 , a computer program loaded into computing system  710  may cause processor  714  to perform and/or be a means for performing the functions of one or more of the exemplary embodiments described and/or illustrated herein. Additionally or alternatively, one or more of the exemplary embodiments described and/or illustrated herein may be implemented in firmware and/or hardware. For example, computing system  710  may be configured as an Application Specific Integrated Circuit (ASIC) adapted to implement one or more of the exemplary embodiments disclosed herein. 
       FIG. 8  is a block diagram of an exemplary network architecture  800  in which client systems  810 ,  820 , and  830  and servers  840  and  845  may be coupled to a network  850 . As detailed above, all or a portion of network architecture  800  may perform and/or be a means for performing, either alone or in combination with other elements, one or more of the steps disclosed herein (such as one or more of the steps illustrated in  FIG. 4 ). All or a portion of network architecture  800  may also be used to perform and/or be a means for performing other steps and features set forth in the instant disclosure. 
     Client systems  810 ,  820 , and  830  generally represent any type or form of computing device or system, such as exemplary computing system  710  in  FIG. 7 . Similarly, servers  840  and  845  generally represent computing devices or systems, such as application servers or database servers, configured to provide various database services and/or run certain software applications. Network  850  generally represents any telecommunication or computer network including, for example, an intranet, a WAN, a LAN, a PAN, or the Internet. In one example, client systems  810 ,  820 , and/or  830  and/or servers  840  and/or  845  may include all or a portion of system  100  from  FIG. 1 . 
     As illustrated in  FIG. 8 , one or more storage devices  860 ( 1 )-(N) may be directly attached to server  840 . Similarly, one or more storage devices  870 ( 1 )-(N) may be directly attached to server  845 . Storage devices  860 ( 1 )-(N) and storage devices  870 ( 1 )-(N) generally represent any type or form of storage device or medium capable of storing data and/or other computer-readable instructions. In certain embodiments, storage devices  860 ( 1 )-(N) and storage devices  870 ( 1 )-(N) may represent Network-Attached Storage (NAS) devices configured to communicate with servers  840  and  845  using various protocols, such as Network File System (NFS), Server Message Block (SMB), or Common Internet File System (CIFS). 
     Servers  840  and  845  may also be connected to a Storage Area Network (SAN) fabric  880 . SAN fabric  880  generally represents any type or form of computer network or architecture capable of facilitating communication between a plurality of storage devices. SAN fabric  880  may facilitate communication between servers  840  and  845  and a plurality of storage devices  890 ( 1 )-(N) and/or an intelligent storage array  895 . SAN fabric  880  may also facilitate, via network  850  and servers  840  and  845 , communication between client systems  810 ,  820 , and  830  and storage devices  890 ( 1 )-(N) and/or intelligent storage array  895  in such a manner that devices  890 ( 1 )-(N) and array  895  appear as locally attached devices to client systems  810 ,  820 , and  830 . As with storage devices  860 ( 1 )-(N) and storage devices  870 ( 1 )-(N), storage devices  890 ( 1 )-(N) and intelligent storage array  895  generally represent any type or form of storage device or medium capable of storing data and/or other computer-readable instructions. 
     In certain embodiments, and with reference to exemplary computing system  710  of  FIG. 7 , a communication interface, such as communication interface  722  in  FIG. 7 , may be used to provide connectivity between each client system  810 ,  820 , and  830  and network  850 . Client systems  810 ,  820 , and  830  may be able to access information on server  840  or  845  using, for example, a web browser or other client software. Such software may allow client systems  810 ,  820 , and  830  to access data hosted by server  840 , server  845 , storage devices  860 ( 1 )-(N), storage devices  870 ( 1 )-(N), storage devices  890 ( 1 )-(N), or intelligent storage array  895 . Although  FIG. 8  depicts the use of a network (such as the Internet) for exchanging data, the embodiments described and/or illustrated herein are not limited to the Internet or any particular network-based environment. 
     In at least one embodiment, all or a portion of one or more of the exemplary embodiments disclosed herein may be encoded as a computer program and loaded onto and executed by server  840 , server  845 , storage devices  860 ( 1 )-(N), storage devices  870 ( 1 )-(N), storage devices  890 ( 1 )-(N), intelligent storage array  895 , or any combination thereof. All or a portion of one or more of the exemplary embodiments disclosed herein may also be encoded as a computer program, stored in server  840 , run by server  845 , and distributed to client systems  810 ,  820 , and  830  over network  850 . 
     As detailed above, computing system  710  and/or one or more components of network architecture  800  may perform and/or be a means for performing, either alone or in combination with other elements, one or more steps of an exemplary method for creating optimized synthetic backup images. 
     While the foregoing disclosure sets forth various embodiments using specific block diagrams, flowcharts, and examples, each block diagram component, flowchart step, operation, and/or component described and/or illustrated herein may be implemented, individually and/or collectively, using a wide range of hardware, software, or firmware (or any combination thereof) configurations. In addition, any disclosure of components contained within other components should be considered exemplary in nature since many other architectures can be implemented to achieve the same functionality. 
     In some examples, all or a portion of exemplary system  100  in  FIG. 1  may represent portions of a cloud-computing or network-based environment. Cloud-computing environments may provide various services and applications via the Internet. These cloud-based services (e.g., software as a service, platform as a service, infrastructure as a service, etc.) may be accessible through a web browser or other remote interface. Various functions described herein may be provided through a remote desktop environment or any other cloud-based computing environment. 
     In various embodiments, all or a portion of exemplary system  100  in  FIG. 1  may facilitate multi-tenancy within a cloud-based computing environment. In other words, the software modules described herein may configure a computing system (e.g., a server) to facilitate multi-tenancy for one or more of the functions described herein. For example, one or more of the software modules described herein may program a server to enable two or more clients (e.g., customers) to share an application that is running on the server. A server programmed in this manner may share an application, operating system, processing system, and/or storage system among multiple customers (i.e., tenants). One or more of the modules described herein may also partition data and/or configuration information of a multi-tenant application for each customer such that one customer cannot access data and/or configuration information of another customer. 
     According to various embodiments, all or a portion of exemplary system  100  in  FIG. 1  may be implemented within a virtual environment. For example, modules and/or data described herein may reside and/or execute within a virtual machine. Additionally or alternatively, the modules and/or data described herein may reside and/or execute within a virtualization layer. As used herein, the phrase “virtualization layer” generally refers to any data layer and/or application layer that overlays and/or is abstracted from an operating system environment. A virtualization layer may be managed by a software virtualization solution (e.g., a file system filter) that presents the virtualization layer as though it were part of an underlying base operating system. For example, a software virtualization solution may redirect calls that are initially directed to locations within a base file system and/or registry to locations within a virtualization layer. 
     In some examples, all or a portion of exemplary system  100  in  FIG. 1  may represent portions of a mobile computing environment. Mobile computing environments may be implemented by a wide range of mobile computing devices, including mobile phones, tablet computers, e-book readers, personal digital assistants, wearable computing devices (e.g., computing devices with a head-mounted display, smartwatches, etc.), and the like. In some examples, mobile computing environments may have one or more distinct features, including, for example, reliance on battery power, presenting only one foreground application at any given time, remote management features, touchscreen features, location and movement data (e.g., provided by Global Positioning Systems, gyroscopes, accelerometers, etc.), restricted platforms that restrict modifications to system-level configurations and/or that limit the ability of third-party software to inspect the behavior of other applications, controls to restrict the installation of applications (e.g., to only originate from approved application stores), etc. Various functions described herein may be provided for a mobile computing environment and/or may interact with a mobile computing environment. 
     In addition, all or a portion of exemplary system  100  in  FIG. 1  may represent portions of, interact with, consume data produced by, and/or produce data consumed by one or more systems for information management. As used herein, the phrase “information management” may refer to the protection, organization, and/or storage of data. Examples of systems for information management may include, without limitation, storage systems, backup systems, archival systems, replication systems, high availability systems, data search systems, virtualization systems, and the like. 
     In some embodiments, all or a portion of exemplary system  100  in  FIG. 1  may represent portions of, produce data protected by, and/or communicate with one or more systems for information security. As used herein, the phrase “information security” may refer to the control of access to protected data. Examples of systems for information security may include, without limitation, systems providing managed security services, data loss prevention systems, identity authentication systems, access control systems, encryption systems, policy compliance systems, intrusion detection and prevention systems, electronic discovery systems, and the like. 
     According to some examples, all or a portion of exemplary system  100  in  FIG. 1  may represent portions of, communicate with, and/or receive protection from one or more systems for endpoint security. As used herein, the phrase “endpoint security” may refer to the protection of endpoint systems from unauthorized and/or illegitimate use, access, and/or control. Examples of systems for endpoint protection may include, without limitation, anti-malware systems, user authentication systems, encryption systems, privacy systems, spam-filtering services, and the like. 
     The process parameters and sequence of steps described and/or illustrated herein are given by way of example only and can be varied as desired. For example, while the steps illustrated and/or described herein may be shown or discussed in a particular order, these steps do not necessarily need to be performed in the order illustrated or discussed. The various exemplary methods described and/or illustrated herein may also omit one or more of the steps described or illustrated herein or include additional steps in addition to those disclosed. 
     While various embodiments have been described and/or illustrated herein in the context of fully functional computing systems, one or more of these exemplary embodiments may be distributed as a program product in a variety of forms, regardless of the particular type of computer-readable-storage media used to actually carry out the distribution. The embodiments disclosed herein may also be implemented using software modules that perform certain tasks. These software modules may include script, batch, or other executable files that may be stored on a computer-readable storage medium or in a computing system. In some embodiments, these software modules may configure a computing system to perform one or more of the exemplary embodiments disclosed herein. 
     In addition, one or more of the modules described herein may transform data, physical devices, and/or representations of physical devices from one form to another. For example, one or more of the modules recited herein may receive a backup image to be transformed, transform the backup image, output a result of the transformation to create a data stream, use the result of the transformation to create a synthetic backup image based at least in part on the data stream, and store the result of the transformation to facilitate restoring a virtual machine from synthetic backup image. Additionally or alternatively, one or more of the modules recited herein may transform a processor, volatile memory, non-volatile memory, and/or any other portion of a physical computing device from one form to another by executing on the computing device, storing data on the computing device, and/or otherwise interacting with the computing device. 
     The preceding description has been provided to enable others skilled in the art to best utilize various aspects of the exemplary embodiments disclosed herein. This exemplary description is not intended to be exhaustive or to be limited to any precise form disclosed. Many modifications and variations are possible without departing from the spirit and scope of the instant disclosure. The embodiments disclosed herein should be considered in all respects illustrative and not restrictive. Reference should be made to the appended claims and their equivalents in determining the scope of the instant disclosure. 
     Unless otherwise noted, the terms “a” or “an,” as used in the specification and claims, are to be construed as meaning “at least one of.” In addition, for ease of use, the words “including” and “having,” as used in the specification and claims, are interchangeable with and have the same meaning as the word “comprising.”