Abstract:
Techniq ues for recovering a virtual machine are disclosed. In one particular embodiment, the techniques may be realized as a method for recovering a virtual machine comprising the steps of selecting a first backup copy of a virtual machine in a first data store, selecting a second data store; enabling use of the virtual machine by reading from the first data store and writing to the second data store, selecting a second backup copy of the virtual machine, and migrating the virtual machine from the second backup copy to the second data store.

Description:
FIELD OF THE DISCLOSURE 
       [0001]    The present disclosure relates generally to virtual machines and, more particularly, to techniques for recovering a virtual machine. 
       BACKGROUND OF THE DISCLOSURE 
       [0002]    A virtual machine (VM), such as VMware ESX or Microsoft Hyper-V Server, enables business processes through virtualized systems. Virtual machines may be backed up, copied, or migrated among different data stores and host computers. In the event of a disruption, conventional systems restore a virtual machine from a backup copy. 
         [0003]    The Recovery Time Objective (RTO) of an application is determined by the time taken to restore a business process to full functionality after a disaster or other disruption. RTO is sometimes determined by the time it takes to restore the relevant data from a backup copy, which can take several hours or longer depending on the amount of data to be restored. 
         [0004]    Some conventional systems attempt to reduce RTO by running the virtual machine directly from its backup copy while simultaneously restoring data from the backup copy to the production server. However, these conventional systems suffer from performance degradation because the backup copy must be shared between both the restoration process and the virtual machine execution process. Additionally, further performance degradation to either process will result depending on whether the backup data store is optimized fast serial memory access beneficial to the restoration process or to fast random memory access beneficial to the execution process. 
         [0005]    In view of the foregoing, it may be understood that there may be significant problems and shortcomings associated with traditional virtual machine recovery technologies. 
       SUMMARY OF THE DISCLOSURE 
       [0006]    Techniques for recovering a virtual machine are disclosed. In one particular embodiment, the techniques may be realized as a method for recovering a virtual machine comprising the steps of selecting a first backup copy of a virtual machine in a first data store, selecting a second data store; enabling use of the virtual machine by reading from the first data store and writing to the second data store, selecting a second backup copy of the virtual machine, and migrating the virtual machine from the second backup copy to the second data store. 
         [0007]    In accordance with further aspects of this particular embodiment, wherein the first data store is optimized for fast random access to backup data. 
         [0008]    In accordance with further aspects of this particular embodiment, wherein the second data store is optimized for fast read and write access to production data. 
         [0009]    In accordance with further aspects of this particular embodiment, wherein the second backup copy is optimized for fast serial access to backup data. 
         [0010]    In accordance with further aspects of this particular embodiment, wherein enabling use of the virtual machine further comprises configuring the virtual machine from a configuration stored in the first backup copy, modifying the configuration to refer to the second data store as a working directory and refer to the first data store for read access, and modifying the copy of the configuration to refer to the second data store for write access. 
         [0011]    In accordance with further aspects of this particular embodiment, wherein enabling use of the virtual machine further comprises creating a snapshot of the virtual machine. 
         [0012]    In accordance with further aspects of this particular embodiment, wherein migrating the virtual machine from the second backup copy to the second data store further comprises incorporating writes written to the second data store while the virtual machine is in use. 
         [0013]    In accordance with additional aspects of this particular embodiment, the method may comprise sending a notification when the virtual machine recovery is complete. 
         [0014]    In another particular exemplary embodiment, the techniques may be realized as a system for recovering a virtual machine comprising one or more processors communicatively coupled to a network, wherein the one or more processors are configured to select a first backup copy of a virtual machine in a first data store select a second data store, enable use of the virtual machine by reading from the first data store and writing to the second data store, select a second backup copy of the virtual machine, and migrate the virtual machine from the second backup copy to the second data store. 
         [0015]    In accordance with additional aspects of this particular embodiment, wherein the first data store is optimized for fast random access to backup data. 
         [0016]    In accordance with additional aspects of this particular embodiment, wherein the second backup copy is optimized for fast serial access to backup data. 
         [0017]    In accordance with additional aspects of this particular embodiment, the one or more processors may be further configured to configure the virtual machine from a configuration of the virtual machine from the first data store to the second data store, modify the copy of the configuration to refer to the second data store as a working directory and refer to the first data store for read access, and modify the copy of the configuration to refer to the second data store for write access. 
         [0018]    In accordance with additional aspects of this particular embodiment, wherein migrate the virtual machine from the second backup copy to the second data store further comprises incorporating writes written to the second data store while the virtual machine is in use. 
         [0019]    In accordance with additional aspects of this particular embodiment, the one or more processors may be further configured to send a notification when the virtual machine recovery is complete. 
         [0020]    In yet another particular exemplary embodiment, the techniques may be realized as an article of manufacture for recovering a virtual machine, the article of manufacture comprising at least one non-transitory processor readable storage medium, and instructions stored on the at least one medium, wherein the instructions are configured to be readable from the at least one medium by at least one processor and thereby cause the at least one processor to operate so as to 
         [0021]    In accordance with additional aspects of this particular embodiment, the instructions may cause the at least one processor to operate further so as to select a first backup copy of a virtual machine in a first data store. select a second data store, enable use of the virtual machine by reading from the first data store and writing to the second data store, select a second backup copy of the virtual machine, and migrate the virtual machine from the second backup copy to the second data store. 
         [0022]    In accordance with additional aspects of this particular embodiment, wherein the first data store is optimized for fast random access to backup data. 
         [0023]    In accordance with additional aspects of this particular embodiment, wherein the second backup copy is optimized for fast serial access to backup data. 
         [0024]    In accordance with additional aspects of this particular embodiment, wherein the instructions cause the at least one processor to operate further so as to configure the virtual machine from a configuration of the virtual machine from the first data store to the second data store, modify the copy of the configuration to refer to the second data store as a working directory and refer to the first data store for read access, and modify the copy of the configuration to refer to the second data store for write access. 
         [0025]    The present disclosure will now be described in more detail with reference to particular embodiments thereof as shown in the accompanying drawings. While the present disclosure is described below with reference to particular embodiments, it should be understood that the present disclosure is not limited thereto. Those of ordinary skill in the art having access to the teachings herein will recognize additional implementations, modifications, and embodiments, as well as other fields of use, which are within the scope of the present disclosure as described herein, and with respect to which the present disclosure may be of significant utility. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    In order to facilitate a fuller understanding of the present disclosure, reference is now made to the accompanying drawings, in which like elements are referenced with like numerals. 
           [0027]    These drawings should not be construed as limiting the present disclosure, but are intended to be illustrative only. 
           [0028]      FIG. 1  shows a block diagram depicting a network architecture for virtual machine recovery in accordance with an embodiment of the present disclosure. 
           [0029]      FIG. 2  depicts a block diagram of a computer system for virtual machine recovery in accordance with an embodiment of the present disclosure. 
           [0030]      FIG. 3  shows a virtual machine recovery module in accordance with an embodiment of the present disclosure. 
           [0031]      FIG. 4  depicts a method for recovering a virtual machine in accordance with an embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0032]      FIG. 1  shows a block diagram depicting a network architecture  100  for virtual machine recovery in accordance with an embodiment of the present disclosure.  FIG. 1  is a simplified view of network architecture  100 , which may include additional elements that are not depicted. Network architecture  100  may contain client systems  110 ,  120  and  130 , as well as servers  140 A and  140 B (one or more of which may be implemented using computer system  200  shown in  FIG. 2 ). Client systems  110 ,  120  and  130  may be communicatively coupled to a network  150 . Server  140 A may be communicatively coupled to storage devices  160 A( 1 )-(N), and server  140 B may be communicatively coupled to storage devices  160 B( 1 )-(N). Servers  140 A and  140 B may contain a management module (e.g., virtual machine recovery module  154  of server  140 A). Servers  140 A and  140 B may be communicatively coupled to a SAN (Storage Area Network) fabric  170 . SAN fabric  170  may support access to storage devices  180 ( 1 )-(N) by servers  140 A and  140 B, and by client systems  110 ,  120  and  130  via network  150 . 
         [0033]    With reference to computer system  200  of  FIG. 2 , modem  247 , network interface  248 , or some other method may be used to provide connectivity from one or more of client systems  110 ,  120  and  130  to network  150 . Client systems  110 ,  120  and  130  may be able to access information on server  140 A or  140 B using, for example, a web browser or other client software (not shown). Such a client may allow client systems  110 ,  120  and  130  to access data hosted by server  140 A or  140 B or one of storage devices  160 A( 1 )-(N),  160 B( 1 )-(N), and/or  180 ( 1 )-(N). 
         [0034]    Networks  150  and  190  may be local area networks (LANs), wide area networks (WANs), the Internet, cellular networks, satellite networks, or other networks that permit communication between clients  110 ,  120 ,  130 , servers  140 , and other devices communicatively coupled to networks  150  and  190 . Networks  150  and  190  may further include one, or any number, of the exemplary types of networks mentioned above operating as a stand-alone network or in cooperation with each other. Networks  150  and  190  may utilize one or more protocols of one or more clients or servers to which they are communicatively coupled. Networks  150  and  190  may translate to or from other protocols to one or more protocols of network devices. Although networks  150  and  190  are each depicted as one network, it should be appreciated that according to one or more embodiments, networks  150  and  190  may each comprise a plurality of interconnected networks. 
         [0035]    Storage devices  160 A( 1 )-(N),  160 B( 1 )-(N), and/or  180 ( 1 )-(N) may be network accessible storage and may be local, remote, or a combination thereof to server  140 A or  140 B. Storage devices  160 A( 1 )-(N),  160 B( 1 )-(N), and/or  180 ( 1 )-(N) may utilize a redundant array of inexpensive disks (“RAID”), magnetic tape, disk, a storage area network (“SAN”), an internet small computer systems interface (“iSCSI”) SAN, a Fibre Channel SAN, a common Internet File System (“CIFS”), network attached storage (“NAS”), a network file system (“NFS”), optical based storage, or other computer accessible storage. Storage devices  160 A( 1 )-(N),  160 B( 1 )-(N), and/or  180 ( 1 )-(N) may be used for backup or archival purposes. 
         [0036]    According to some embodiments, clients  110 ,  120 , and  130  may be smartphones, PDAs, desktop computers, a laptop computers, servers, other computers, or other devices coupled via a wireless or wired connection to network  150 . Clients  110 ,  120 , and  130  may receive data from user input, a database, a file, a web service, and/or an application programming interface. 
         [0037]    Servers  140 A and  140 B may be application servers, archival platforms, backup servers, network storage devices, media servers, email servers, document management platforms, enterprise search servers, or other devices communicatively coupled to network  150 . Servers  140 A and  140 B may utilize one of storage devices  160 A( 1 )-(N),  160 B( 1 )-(N), and/or  180 ( 1 )-(N) for the storage of application data, backup data, or other data. Servers  140 A and  140 B may be hosts, such as an application server, which may process data traveling between clients  110 ,  120 , and  130  and a backup platform, a backup process, and/or storage. According to some embodiments, servers  140 A and  140 B may be platforms used for backing up and/or archiving data. One or more portions of data may be backed up or archived based on a backup policy and/or an archive applied, attributes associated with the data source, space available for backup, space available at the data source, or other factors. 
         [0038]    According to some embodiments, clients  110 ,  120 , and/or  130  may contain one or more portions of software for virtual machine recovery such as, for example, virtual machine recovery module  154 . As illustrated, one or more portions of virtual machine recovery module  154  may reside at a network centric location. For example, server  140 A may be a server, a firewall, a gateway, or other network element that may perform one or more actions to scan web applications for vulnerabilities. According to some embodiments, network  190  may be an external network (e.g., the Internet) and server  140 A may be a gateway or firewall between one or more internal components and clients and the external network. According to some embodiments, virtual machine recovery module  154  may be implemented as part of a cloud computing environment. 
         [0039]      FIG. 2  depicts a block diagram of a computer system  200  for virtual machine recovery in accordance with an embodiment of the present disclosure. Computer system  200  is suitable for implementing techniques in accordance with the present disclosure. Computer system  200  may include a bus  212  which may interconnect major subsystems of computer system  200 , such as a central processor  214 , a system memory  217  (e.g. RAM (Random Access Memory), ROM (Read Only Memory), flash RAM, or the like), an Input/Output (I/O) controller  218 , an external audio device, such as a speaker system  220  via an audio output interface  222 , an external device, such as a display screen  224  via display adapter  226 , serial ports  228  and  230 , a keyboard  232  (interfaced via a keyboard controller  233 ), a storage interface  234 , a floppy disk drive  237  operative to receive a floppy disk  238 , a host bus adapter (HBA) interface card  235 A operative to connect with a Fibre Channel network  290 , a host bus adapter (HBA) interface card  235 B operative to connect to a SCSI bus  239 , and an optical disk drive  240  operative to receive an optical disk  242 . Also included may be a mouse  246  (or other point-and-click device, coupled to bus  212  via serial port  228 ), a modem  247  (coupled to bus  212  via serial port  230 ), network interface  248  (coupled directly to bus  212 ), power manager  250 , and battery  252 . 
         [0040]    Bus  212  allows data communication between central processor  214  and system memory  217 , which may include read-only memory (ROM) or flash memory (neither shown), and random access memory (RAM) (not shown), as previously noted. The RAM may be the main memory into which the operating system and application programs may be loaded. The ROM or flash memory can contain, among other code, the Basic Input-Output system (BIOS) which controls basic hardware operation such as the interaction with peripheral components. Applications resident with computer system  200  may be stored on and accessed via a computer readable medium, such as a hard disk drive (e.g., fixed disk  244 ), an optical drive (e.g., optical drive  240 ), a floppy disk unit  237 , or other storage medium. For example, virtual machine recovery module  154  may be resident in system memory  217 . 
         [0041]    Storage interface  234 , as with the other storage interfaces of computer system  200 , can connect to a standard computer readable medium for storage and/or retrieval of information, such as a fixed disk drive  244 . Fixed disk drive  244  may be a part of computer system  200  or may be separate and accessed through other interface systems. Modem  247  may provide a direct connection to a remote server via a telephone link or to the Internet via an internet service provider (ISP). Network interface  248  may provide a direct connection to a remote server via a direct network link to the Internet via a POP (point of presence). Network interface  248  may provide such connection using wireless techniques, including digital cellular telephone connection, Cellular Digital Packet Data (CDPD) connection, digital satellite data connection or the like. 
         [0042]    Many other devices or subsystems (not shown) may be connected in a similar manner (e.g., document scanners, digital cameras and so on). Conversely, all of the devices shown in  FIG. 2  need not be present to practice the present disclosure. The devices and subsystems can be interconnected in different ways from that shown in  FIG. 2 . Code to implement the present disclosure may be stored in computer-readable storage media such as one or more of system memory  217 , fixed disk  244 , optical disk  242 , or floppy disk  238 . Code to implement the present disclosure may also be received via one or more interfaces and stored in memory. The operating system provided on computer system  200  may be MS-DOS®, MS-WINDOWS®, OS/2®, OS X®, UNIXO, Linux®, or another known operating system. 
         [0043]    Power manager  250  may monitor a power level of battery  252 . Power manager  250  may provide one or more APIs (Application Programming Interfaces) to allow determination of a power level, of a time window remaining prior to shutdown of computer system  200 , a power consumption rate, an indicator of whether computer system is on mains (e.g., AC Power) or battery power, and other power related information. According to some embodiments, APIs of power manager  250  may be accessible remotely (e.g., accessible to a remote backup management module via a network connection). According to some embodiments, battery  252  may be an Uninterruptable Power Supply (UPS) located either local to or remote from computer system  200 . In such embodiments, power manager  250  may provide information about a power level of an UPS. 
         [0044]    Referring to  FIG. 3 , there is shown a virtual machine recovery module  310  in accordance with an embodiment of the present disclosure. As illustrated, the virtual machine recovery module  310  may contain one or more components including virtual machine backup management module  312 , virtual machine data store management module  314 , virtual machine configuration management module  316 , and virtual machine migration management module  318 . 
         [0045]    The description below describes network elements, computers, and/or components of a system and method for virtual machine recovery that may include one or more modules. As used herein, the term “module” may be understood to refer to computing software, firmware, hardware, and/or various combinations thereof. Modules, however, are not to be interpreted as software which is not implemented on hardware, firmware, or recorded on a processor readable recordable storage medium (i.e., modules are not software per se). It is noted that the modules are exemplary. The modules may be combined, integrated, separated, and/or duplicated to support various applications. Also, a function described herein as being performed at a particular module may be performed at one or more other modules and/or by one or more other devices instead of or in addition to the function performed at the particular module. Further, the modules may be implemented across multiple devices and/or other components local or remote to one another. Additionally, the modules may be moved from one device and added to another device, and/or may be included in both devices. 
         [0046]    According to some embodiments, virtual machine backup management module  312  may manage backup copies of virtual machines. The backup module  312  may maintain multiple copies of a virtual machine. The copies may be written to one or more storage systems and configured for read-only access in the event that recovery from a backup copy is desired. In some embodiments, one or more copies of a virtual machine may be stored in a data store optimized for fast random access. In some embodiments, one or more copies of a virtual machine may be stored in a data store optimized for fast serial access. 
         [0047]    When recovery is desired, the backup module  312  may select a first backup copy for use by a virtual machine execution process. The execution process may read the virtual machine data from the first backup copy and enables use of the virtual machine by an end user. In some embodiments, the backup module  312  may select the first backup copy from a first data store optimized for fast random access to improve the performance of the execution process. 
         [0048]    When recovery is desired, the backup module  312  may select a second backup copy for use by a virtual machine restoration process. The restoration process may read the virtual machine data from the second backup copy and enables restoration of the virtual machine to a production data store. The restoration process may include copying or migrating virtual machine data from one data store to another. In some embodiments, the backup module  312  may select the second backup copy from a second data store optimized for fast serial access to improve the performance of the restoration process. 
         [0049]    According to some embodiments, the backup module  312  may be in communication with the virtual machine data store management module  314  to facilitate selecting data stores where the first and second backup copies are stored. 
         [0050]    The data store module  314  manages the data stores in which virtual machine data is stored. The data store module  314  may manage data stores wherever they exist. In some embodiments, they may exist on remote servers, while in other embodiments they may be collocated with the data store module  314 . A data store may be part of a cloud computing environment or a virtualized storage environment. Data stores may be configurable to be read only or for both read and write access. A backup data store may be dedicated for storing one or more backup copies of virtual machines, and a production data store may be dedicated to storing one or more production copies of virtual machines. A backup store may be optimized for either fast random access or fast serial access. 
         [0051]    When recovery is desired, the data store module  314  may select a second data store to which the virtual machine may be recovered. The second data store may be used to store the production writes in a redo log during recovery. The second data store may also be used to store the virtual machine data as it is recovered from the backup copy to the new production copy. 
         [0052]    According to some embodiments, the data store module  314  and the backup module  312  may be in communication with the virtual machine configuration management module  316  to facilitate modifying virtual machine configurations to refer to the backup copies and data stores where the backup copies are stored. A virtual machine configuration, such as a VMX file for a VMware ESX virtual machine, may include a reference to a particular copy of a virtual machine or a particular data store where the copy of the virtual machine is stored. In some embodiments, the configuration module  316  may modify one or more configurations of one or more virtual machines. 
         [0053]    When recovery is desired, the configuration module  316  may copy files associated with the configuration of the first backup copy to the second data store that may receive production writes and the recovered virtual machine data. The configuration module  316  may modify a copy of the configuration to designate the first backup for production reads and the second data store for production writes during recovery. In some embodiments, after the virtual machine data has been restored to the second data store, the configuration module  316  may modify one or more copies of the configuration to designate the second data store for both production reads and production writes. The configuration module  316  may remove or disable any references to the first backup copy that is no longer being used for production reads. 
         [0054]    According to some embodiments, the configuration module  316  may be in communication with the virtual machine migration management module  318  for facilitating migration of data for one or more virtual machines. Migration of a virtual machine may include moving or copying virtual machine data from one data store to another. In some embodiments, most or all of the migration can occur while one or more processes are using the virtual machine data. For example, a virtual machine may be instantly recovered for use during the recovery process. In some embodiments, the migration module  318  may, as desired, boot a virtual machine, suspend a booted virtual machine, resume a suspended virtual machine, stop or shut down a virtual machine, move, copy, send notification about the state of a virtual machine, or otherwise migrate a virtual machine, and incorporate changes to a virtual machine that occurred during migration. 
         [0055]    When recovery is desired, the migration module  318  may communicate with the backup module  312  to facilitate selection of the first backup copy to use for the execution process. The migration module  318  may further communicate with the data store module  314  and the configuration module  316  to facilitate selection of the second data store to receive production writes in a redo log for the execution process and configure as a working directory for a virtual machine. After the configuration module  316  may copy and modify a configuration for the virtual machine according to the first backup copy and the second data store, the migration module  318  may create a snapshot of the virtual machine and boot the the virtual machine . The migration module  318  may optionally notify another module, user, or system administrator that the virtual machine has been recovered and is ready for use. 
         [0056]    In some embodiments, the migration module  318  may further communicate with the data store module  314  to facilitate selection a second backup copy to migrate. In some embodiments, the second backup copy may be stored in a data store optimized for fast serial access. The migration module  318  may initiate a migration of the virtual machine data in the second backup copy to the second data store selected to receive the recovered virtual machine data. For example, in some embodiments, migration may be performed as a background restore process that may be part of Symantec NetBackup. In other embodiments, migration may be performed by VMware Storage vMotion. When migration is complete, the migration module  318  may temporarily suspend or stop the virtual machine to facilitate the configuration module  316  may modify the configuration to refer to the completely migrated virtual machine data. After the configuration has been modified, the migration module  318  may resume or restart the virtual machine. 
         [0057]    Referring to  FIG. 4 , there is depicted a method  400  for recovering a virtual machine in accordance with an embodiment of the present disclosure. At block  402 , the method  400  may begin. 
         [0058]    At block  404 , a first backup copy of a virtual machine may be selected from a first data store. In some embodiments, the first data store may be optimized for fast random access for use by an execution process. 
         [0059]    At block  406 , a second data store that is different from the first data store may be selected. In some embodiments, the second data store may be optimized for fast serial access for use by a restoration or migration process. The first and second data stores may be on remotely networked systems, cloud storage, or virtual storage systems. In other embodiments, the data stores may be co-located. 
         [0060]    At block  408 , a virtual machine may be configured at the second data store selected at block  406  based on the configuration stored in the first backup selected at block  404 . 
         [0061]    At block  410 , the configuration may be modified to refer to the second data store selected at block  406  to be used as a working directory. The configuration information may be modified further to refer to the first backup copy for production reads within the execution process. 
         [0062]    At block  412 , a snapshot of the virtual machine may be created to refer to the second data store to store production writes within the execution process. In some embodiments, production writes may be stored in a redo log. 
         [0063]    At block  414 , the virtual machine may be booted. 
         [0064]    At block  416 , a notification may be sent that the snapshot of the virtual machine has been booted and is ready for production use in an execution process. Following block  414  and optional block  416 , the virtual machine has been recovered with full read and write functionality. In some embodiments, performance may be improved during production reads if the first data store has been optimized for random access. At this point, the recovered virtual machine reads data from the first backup copy in the first data store and writes data to the redo log in the second data store. 
         [0065]    At block  418 , a background restore of the virtual machine data may be initiated from a second backup copy different from the first backup copy. In some embodiments, the second backup copy may be optimized for fast serial access to improve performance of a restoration or migration process. In some embodiments, the background restore may be initiated from a plurality of backup copies different from the first backup copy in parallel to improve performance further. In some embodiments, the background restore may use a SAN transfer medium to improve performance further still. 
         [0066]    At block  420 , after the background restore of the second backup copy to the production copy in the second data store is complete, the configuration of the virtual machine may be modified to refer to the restored copy for production reads and writes in an execution process. In some embodiments, the snapshot of the virtual machine may be temporarily suspended or shut down to facilitate modifying the configuration, then the virtual machine may be resumed or restarted after the configuration has been modified. 
         [0067]    At block  422 , a notification may be sent that the recovery and restoration process is complete. 
         [0068]    At block  424 , the method  400  may end. 
         [0069]    At this point it should be noted that virtual machine recovery in accordance with the present disclosure as described above may involve the processing of input data and the generation of output data to some extent. This input data processing and output data generation may be implemented in hardware or software. For example, specific electronic components may be employed in a virtual machine recovery module or similar or related circuitry for implementing the functions associated with virtual machine recovery in accordance with the present disclosure as described above. Alternatively, one or more processors operating in accordance with instructions may implement the functions associated with virtual machine recovery in accordance with the present disclosure as described above. If such is the case, it is within the scope of the present disclosure that such instructions may be stored on one or more non-transitory processor readable storage media (e.g., a magnetic disk or other storage medium), or transmitted to one or more processors via one or more signals embodied in one or more carrier waves. 
         [0070]    The present disclosure is not to be limited in scope by the specific embodiments described herein. Indeed, other various embodiments of and modifications to the present disclosure, in addition to those described herein, will be apparent to those of ordinary skill in the art from the foregoing description and accompanying drawings. Thus, such other embodiments and modifications are intended to fall within the scope of the present disclosure. Further, although the present disclosure has been described herein in the context of at least one particular implementation in at least one particular environment for at least one particular purpose, those of ordinary skill in the art will recognize that its usefulness is not limited thereto and that the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in view of the full breadth and spirit of the present disclosure as described herein.