Systems and methods for taking snapshots in a deduplicated virtual file system

A computer-implemented method for taking snapshots in a deduplicated virtual file system may include (1) maintaining a deduplicated virtual file system that stores, at an original location within a non-virtual file system, at least one configuration file storing metadata for a target file and an extent map for the target file, the extent map defining how to construct the target file from deduplicated data segments in a deduplicated storage system, (2) receiving a request to take a snapshot of the target file corresponding to the configuration file, (3) copying the configuration file storing metadata for the target file and the extent map for the target file into a snapshot location within the non-virtual file system, and (4) transmitting a file reference request to the deduplicated storage system to add a file reference within the deduplicated storage system. Various other methods, systems, and computer-readable media are also disclosed.

BACKGROUND

Individuals and organizations typically seek to protect their private data using a variety of data protection mechanisms. One traditional method for protecting an enterprise organization's data corresponds to taking a “snapshot” of that data. In general, a “snapshot” may refer to any one of several different mechanisms for storing data that preserve the exact content of the data at a specific point in time.

Additionally, as the size of an enterprise organization's data grows, the organization may attempt to address storage space concerns in a variety of ways. For example, the organization may increase physical capacity or implement a form of data compression. In a more specific example, the organization may implement a deduplication system that effectively compresses data by reducing redundant copies of repeated data segments, as discussed further below. Nevertheless, traditional systems for taking snapshots in deduplicated data systems have proven to be non-optimal along a number of dimensions. Specifically, traditional systems may be unduly slow, may degrade in performance as the frequency of taking snapshots increases, and may render snapshots dependent on each other such that modifying or deleting one snapshot needlessly impacts another snapshot. Accordingly, the instant disclosure identifies and addresses a need for additional and improved systems and methods for taking snapshots in a deduplicated virtual file system.

SUMMARY

As will be described in greater detail below, the instant disclosure generally relates to systems and methods for taking snapshots in a deduplicated virtual file system by, for example, copying the non-virtual configuration file or files that store metadata and the extent map for a corresponding target file (i.e., targeted for snapshotting) and also transmitting a file reference request to an associated deduplicated storage system, as discussed further below. In one example, a computer-implemented method for storing data may include (1) maintaining a deduplicated virtual file system that stores, at an original location within a non-virtual file system, at least one configuration file storing metadata for a target file and an extent map for the target file, the extent map defining how to construct the target file from deduplicated data segments in a deduplicated storage system, (2) receiving a request to take a snapshot of the target file corresponding to the configuration file, (3) copying, in response to receiving the request to take the snapshot of the target file, the configuration file storing metadata for the target file and the extent map for the target file into a snapshot location within the non-virtual file system that is different than the original location, and (4) transmitting, in response to receiving the request to take the snapshot of the target file, a file reference request to the deduplicated storage system to add a file reference within the deduplicated storage system, the file reference indicating that the snapshot of the target file references at least one deduplicated data segment within the deduplicated storage system.

In one embodiment, the configuration file stores at least the metadata for the target file and the original location of the configuration file includes a metadata directory. In one embodiment, the configuration file stores at least the extent map for the target file and the original location of the configuration file includes a map directory.

In one example, the original location of the configuration file may include a directory and the snapshot location of the configuration file may include a subdirectory of the directory. In another embodiment, the subdirectory of the directory is created in response to receiving the request to take the snapshot. In some examples, creating the subdirectory of the directory may include assigning the subdirectory a name of the snapshot that was assigned to the snapshot prior to creating the subdirectory.

In one embodiment, the configuration file may correspond to multiple files including both a file storing the metadata for the target file and a separate file storing the extent map for the target file. In another embodiment, the computer-implemented method may further include identifying, by the deduplicated storage system, the deduplicated data segment referenced by the snapshot of the target file and marking, by the deduplicated storage system, the deduplicated data segment as referenced by the snapshot of the target file to prevent removal of the deduplicated data segment. In a further embodiment, the computer-implemented method may include marking, by the deduplicated storage system, each deduplicated data segment referenced by the snapshot of the target file as referenced by the snapshot of the target file to prevent removal of the respective deduplicated data segment.

In one embodiment, the computer-implemented method may further include modifying content of the snapshot. After modifying the snapshot, the computer-implemented method may further include modifying the extent map stored at the snapshot location to reference both (1) an additional deduplicated data segment that the snapshot newly references due to the modifying and (2) an additional deduplication container storing the additional deduplicated data segment separate from an original deduplication container storing the deduplicated data segment of the snapshot prior to the modifying.

In one embodiment, a system for implementing the above-described method may include (1) a maintenance module, stored in memory, that maintains a deduplicated virtual file system that stores, at an original location within a non-virtual file system, at least one configuration file storing metadata for a target file and an extent map for the target file, the extent map defining how to construct the target file from deduplicated data segments in a deduplicated storage system, (2) a reception module, stored in memory, that receives a request to take a snapshot of the target file corresponding to the configuration file, (3) a copying module, stored in memory, that copies, in response to receiving the request to take the snapshot of the target file, the configuration file storing metadata for the target file and the extent map for the target file into a snapshot location within the non-virtual file system that is different than the original location, (4) a transmission module, stored in memory, that transmits, in response to receiving the request to take the snapshot of the target file, a file reference request to the deduplicated storage system to add a file reference within the deduplicated storage system, the file reference indicating that the snapshot of the target file references at least one deduplicated data segment within the deduplicated storage system, and (5) at least one physical processor configured to execute the maintenance module, the reception module, the copying module, and the transmission module.

In some examples, the above-described method may be encoded as computer-readable instructions on a non-transitory computer-readable medium. For example, a computer-readable 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) maintain a deduplicated virtual file system that stores, at an original location within a non-virtual file system, at least one configuration file storing metadata for a target file and an extent map for the target file, the extent map defining how to construct the target file from deduplicated data segments in a deduplicated storage system, (2) receive a request to take a snapshot of the target file corresponding to the configuration file, (3) copy, in response to receiving the request to take the snapshot of the target file, the configuration file storing metadata for the target file and the extent map for the target file into a snapshot location within the non-virtual file system that is different than the original location, and (4) transmit, in response to receiving the request to take the snapshot of the target file, a file reference request to the deduplicated storage system to add a file reference within the deduplicated storage system, the file reference indicating that the snapshot of the target file references at least one deduplicated data segment within the deduplicated storage system.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The present disclosure is generally directed to systems and methods for taking snapshots in a deduplicated virtual file system. As will be explained in greater detail below, the disclosed systems and methods may improve the speed of taking snapshots in deduplicated virtual file systems. Additionally, the disclosed systems and methods may prevent the degradation of performance of taking snapshots as the frequency of taking snapshots increases. Furthermore, the disclosed systems and methods may enable snapshots to be independent of each other such that modifying or deleting one snapshot does not necessarily impact another, as discussed further below.

The following will provide, with reference toFIGS. 1-2, detailed descriptions of exemplary systems for taking snapshots in a deduplicated virtual file system. Detailed descriptions of corresponding computer-implemented methods will also be provided in connection withFIGS. 3-6. 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 withFIGS. 7 and 8, respectively.

FIG. 1is a block diagram of exemplary system100for storing data. As illustrated in this figure, exemplary system100may include one or more modules102for performing one or more tasks. For example, and as will be explained in greater detail below, exemplary system100may also include a maintenance module104that may maintain a deduplicated virtual file system that stores, at an original location within a non-virtual file system, at least one configuration file storing metadata for a target file and an extent map for the target file. The extent map may define how to construct the target file from deduplicated data segments in a deduplicated storage system. Exemplary system100may additionally include a reception module106that may receive a request to take a snapshot of the target file corresponding to the configuration file.

Exemplary system100may also include a copying module108that may copy, in response to receiving the request to take the snapshot of the target file, the configuration file storing metadata for the target file and the extent map for the target file into a snapshot location within the non-virtual file system that is different than the original location. Exemplary system100may additionally include a transmission module110that may transmit, in response to receiving the request to take the snapshot of the target file, a file reference request to the deduplicated storage system to add a file reference within the deduplicated storage system. The file reference may indicate that the snapshot of the target file references at least one deduplicated data segment within the deduplicated storage system. Although illustrated as separate elements, one or more of modules102inFIG. 1may represent portions of a single module or application.

As illustrated inFIG. 1, exemplary system100may also include one or more databases, such as database120. In one example, database120may be configured to store deduplicated data segments122, which may correspond to unique portions of data that the deduplicated storage system uses to construct underlying non-virtual files, as discussed further below. Specifically, the deduplicated storage system may identify a portion of data within the non-virtual file that appears within the non-virtual file multiple times but store the portion of data within the deduplicated storage system only once (e.g., with corresponding metadata instructions indicating where to copy and repeat the portion), thereby potentially reducing storage space. As further shown in the figure, database120may also be configured to store file references124, which may indicate which files reference which deduplicated data segments, thereby preventing removal of data segments that the virtual file system needs to reconstruct corresponding non-virtual files.

Database120may represent portions of a single database or computing device or a plurality of databases or computing devices. For example, database120may represent a portion of computing system710inFIG. 7, and/or portions of exemplary network architecture800inFIG. 8. Alternatively, database120inFIG. 1may represent one or more physically separate devices capable of being accessed by a computing device, such as computing system710inFIG. 7and/or portions of exemplary network architecture800inFIG. 8.

Exemplary system100inFIG. 1may be implemented in a variety of ways. For example, all or a portion of exemplary system100may represent portions of exemplary system200inFIG. 2. As shown inFIG. 2, system200may include a computing device202. In one example, computing device202may be programmed with one or more of modules102and/or may store all or a portion of the data in database120.

In one embodiment, one or more of modules102fromFIG. 1may, when executed by at least one processor of computing device202, enable computing device202to take snapshots in a deduplicated virtual file system. For example, and as will be described in greater detail below, maintenance module104may maintain a deduplicated virtual file system210that stores, at an original location222within a non-virtual file system220, at least one configuration file224storing metadata226for a target file228and an extent map212for target file228. Extent map212may define how to construct target file228from deduplicated data segments122in a deduplicated storage system230. Reception module106may receive a request214to take a snapshot of target file228corresponding to configuration file224. Copying module108may copy, in response to receiving request214to take the snapshot of target file228, configuration file224storing metadata226for target file228and extent map212for target file228into a snapshot location242within non-virtual file system220that is different than original location222. Transmission module110may transmit, in response to receiving request214to take the snapshot of target file228, a file reference request250to deduplicated storage system230to add a file reference within deduplicated storage system230. The file reference may indicate that the snapshot of target file228references at least one deduplicated data segment within deduplicated storage system230.

Computing device202generally represents any type or form of computing device capable of reading computer-executable instructions. Examples of computing device202include, without limitation, laptops, tablets, desktops, servers, cellular phones, Personal Digital Assistants (PDAs), multimedia players, embedded systems, wearable devices (e.g., smart watches, smart glasses, etc.), gaming consoles, combinations of one or more of the same, exemplary computing system710inFIG. 7, or any other suitable computing device.

FIG. 3is a flow diagram of an exemplary computer-implemented method300for taking snapshots in a deduplicated virtual file system. The steps shown inFIG. 3may be performed by any suitable computer-executable code and/or computing system. In some embodiments, the steps shown inFIG. 3may be performed by one or more of the components of system100inFIG. 1, system200inFIG. 2, computing system710inFIG. 7, and/or portions of exemplary network architecture800inFIG. 8.

As illustrated inFIG. 3, at step302, one or more of the systems described herein may maintain a deduplicated virtual file system that stores, at an original location within a non-virtual file system, at least one configuration file storing metadata for a target file and an extent map for the target file, the extent map defining how to construct the target file from deduplicated data segments in a deduplicated storage system. For example, maintenance module104may, as part of computing device202inFIG. 2, maintain deduplicated virtual file system210that stores, at original location222within non-virtual file system220, configuration file224storing metadata226for target file228and/or extent map212for target file228.

As used herein, the term “deduplicated virtual file system” generally refers to a storage system that deduplicates data by storing deduplicated data segments within an associated deduplicated storage system and storing corresponding metadata and file reconstruction information (e.g., extent map212, which indicates how to reconstruct target file228) within a conventional, non-virtual, and/or non-deduplicated file system. Moreover, as used herein, the term “non-virtual file system” simply refers to any file system that does not constitute a “deduplicated virtual file system,” as outlined above. Notably, as used herein, the term “deduplicated virtual file system” refers to an overall files system, or “meta-file-system” that leverages both a conventional or non-virtual file system (i.e., for storing configuration, metadata, and/or extent map information) and a deduplicated storage system (i.e., for storing the deduplicated data segments).

Additionally, as used herein, the term “location” generally refers to any location, such as a directory, within a file system for storing data. Furthermore, as used herein, the term “target file” simply refers to any file that becomes the target for taking a snapshot in accordance with method300, as outlined further below.

Additionally, as used herein, the term “metadata” generally refers to data describing attributes of files stored using the deduplicated storage system. Items of metadata may include timestamps and file size values, for example. Furthermore, as used herein, the term “extent map” generally refers to any map that defines how to reconstruct a file that has been deduplicated from deduplicated data segments stored within the corresponding deduplicated storage system (e.g., maps logical file blocks to deduplicated data segments).

Maintenance module104may maintain the deduplicated virtual file system in a variety of ways. In general, maintenance module104may maintain the deduplicated virtual file system by providing or implementing the deduplicated virtual file system. For example, maintenance module104may maintain the deduplicated virtual file system by optionally deduplicating data and then storing the deduplicated data segments within an associated deduplicated storage system, such as deduplicated storage system230, as well as storing the associated metadata and/or extent map within a non-virtual file system, as discussed above.

In some examples, the configuration file stores at least the metadata for the target file and the original location of the configuration file includes a metadata directory. For example, the metadata directory may be assigned the name or identifier “head.” Additionally, or alternatively, the configuration file stores at least the extent map for the target file and the original location of the configuration file includes a map directory. For example, the map directory may be assigned the name or identifier “map.” Moreover, the configuration file may correspond to multiple files, which include both a file storing the metadata for the target file and a separate file storing the extent map for the target file.

Furthermore, in some examples, the original location of the configuration file includes a directory and the snapshot location of the configuration file includes a subdirectory of the directory. Additionally, in further examples, the configuration file may be automatically assigned, by the deduplicated virtual file system, the same file name as the target file.

FIG. 4shows, on the left side, a graphical user interface402that further displays a directory404, which corresponds to original location222. Directory404may store the original version of target file228by storing metadata226and extent map212that references the deduplicated stored system. As further shown in this figure, directory404may also store a head directory406and a map directory408(i.e., as subdirectories of directory404), which may store metadata226and extent map212, respectively.FIG. 4will also be discussed in further detail regarding step306of method300.

At step304, one or more of the systems described herein may receive a request to take a snapshot of the target file corresponding to the configuration file. For example, reception module106may, as part of computing device202inFIG. 2, receive request214to take the snapshot of target file228corresponding to configuration file224.

Reception module106may receive the request to take the snapshot of the target file in any suitable manner. In general, reception module106may receive input from a user, administrator, and/or another software component in a manual, automated, or semi-automated manner. A user may issue the request to take the snapshot of the target file using any suitable input device, such as a mouse or keyboard. Additionally, or alternatively, reception module106may receive the request to take the snapshot of the target file in accordance with a predefined schedule and/or data backup policy.

At step306, one or more of the systems described herein may copy, in response to receiving the request to take the snapshot of the target file, the configuration file storing metadata for the target file and the extent map for the target file into a snapshot location within the non-virtual file system that is different than the original location. For example, copying module108may, as part of computing device202inFIG. 2, copy, in response to receiving request214to take the snapshot of target file228, configuration file224storing metadata226for target file228and extent map212for target file228into snapshot location242within non-virtual file system220that is different than original location222.

As used herein, the term “snapshot location” generally refers to any location, such as a file system directory or subdirectory, that becomes the location for storing metadata226and/or extent map212for the snapshot, as distinct from the original location or locations for the original target file from which the snapshot is taken. As shown inFIG. 4, on the right side, copying module108has copied metadata226and extent map212from directory404into another directory410. Specifically, copying module108has created directory410as a subdirectory under directory404. Additionally, copying module108has also created copies of head directory406and map directory408in the form of a head directory412and a map directory414, which constitute subdirectories under directory410.

In these examples, each head directory may store a metadata file for every deduplicated file originally stored in the directory under which the head directory is a subdirectory. Similarly, each map directory may store an extent map file for every deduplicated file originally stored in the directory under which the map directory as a subdirectory. In other embodiments, the metadata file and the extent map file may be combined into a single file. Similarly, in other embodiments, the metadata file and/or the extent map file for one deduplicated file may be combined with the metadata file and/or the extent map file for another deduplicated file. In general one or more of these items of information may be aggregated into one or more centralized files.

In the example ofFIG. 4, directory410may correspond to snapshot location242. Moreover, copying module108may create snapshot location242(e.g., directory410) in response to reception of the request to take the snapshot of the target file. Additionally, copying module108may assign or label directory410with a name or label of the snapshot that was previously assigned to the snapshot prior to creation of directory410. Notably, in this example, snapshot location242constitutes a subdirectory of original location222, but in other examples snapshot location242may constitute a separate directory or other location outside of the original location and/or the original directory.

At step308, one or more of the systems described herein may transmit, in response to receiving the request to take the snapshot of the target file, a file reference request to the deduplicated storage system to add a file reference within the deduplicated storage system. The file reference may indicate that the snapshot of the target file references at least one deduplicated data segment within the deduplicated storage system. For example, transmission module110may, as part of computing device202inFIG. 2, transmit, in response to receiving request214to take the snapshot of target file228, file reference request250to deduplicated storage system230to add a file reference within deduplicated storage system230.

As used herein, the term “file reference request” generally refers to any request to a deduplicated storage system to recognize that a corresponding file references one or more deduplicated data segments stored by the deduplicated storage system. In other words, the deduplicated virtual file system needs the corresponding deduplicated data segments to reconstruct or reproduce the file and so the deduplicated storage system should not delete those data segments.

Transmission module110may transmit the file reference request in a variety of ways. For example, transmission module110may instruct the deduplicated storage system, in response to receiving the file reference request, to identify at least one deduplicated data segment, such as segment504, referenced by the snapshot of the target file. Additionally, transmission module110may instruct the deduplicated storage system, in response to receiving the file reference request, to mark (e.g., mark within file references124) the deduplicated data segment as referenced by the snapshot of the target file to prevent removal of the deduplicated data segment. In further examples, transmission module110may instruct the deduplicated storage system to similarly mark each and every deduplicated data segment referenced by the snapshot of the target file.

To help understand how transmission module110performs step308,FIGS. 5 and 6show file references124within deduplicated storage system230. InFIG. 5, reception module104has not yet received the request to take the snapshot of the target file. As shown in this figure, deduplicated storage system230may store deduplicated data segments122, which may further include an original container502that stores all of the deduplicated data segments referenced by the original version of target file228. As further shown in this figure, which is simplified for illustration purposes, target file228(when reconstructed from underlying data segments) is composed of strings of text, some of which are repeated or duplicated throughout target file228. Specifically, the reconstructed version of target file228includes multiple instances of the string “XYX” and the string “ABC.” Accordingly, deduplicated storage system230has deduplicated target file228by only storing a single instance of a segment504(“XYX”), a single instance of a segment506(“ABC”), and a single instance of a segment508(“123”). (The dashed lines around target file228inFIG. 5indicate that the non-deduplicated version of the file is not actually stored within deduplicated storage system230; instead, sufficient information for reconstructing the file from deduplicated data segments122is stored within extent map212, as discussed above.)

Configuration or reconstruction information for reconstructing target file228from these data segments may be stored within extent map212, as further shown in this figure. Specifically, extent map212may include a reference to a segment504, and an indication that segment504is stored within original container502, a reference to segment506, and an indication that segment506is stored within original container502, and a reference to segment508, and an indication that segment508is stored within original container502. Extent map212may also include information on the locations and/or repetitions within target file228where these data segments should be inserted, located, and/or copied to effectively reconstruct target file228.

In the example ofFIG. 5, file references124may indicate which files reference which deduplication containers, such as original container502. In other examples, file references124may more specifically or granularly indicate, not just which files reference which deduplication containers, but also (additionally or alternatively) indicate which files reference which specific data segments. As used herein, the term “deduplicated container” generally refers to any logical container, directory, and/or location within a file system or other storage for storing deduplicated data segments as an aggregated set.

In contrast toFIG. 5,FIG. 6shows how extent map212and deduplicated storage system230may be updated after all of the following: (1) the snapshot is taken of the target file (e.g., in response to the request received as step304) and (2) the snapshot of the target file is modified, as discussed further below. Specifically, file references124show that, after taking the snapshot of the original target file, the snapshot has been modified by substituting the string “456” for the string “123” previously stored at the same location within the target file. Accordingly, file references124have been updated to show that original container502is referenced by the original target file (“test.txt” in this example), because the original target file still references segment504, segment506, and segment508, as previously shown inFIG. 5. Similarly, file references124have been updated to show that original container502is referenced by the modified snapshot (“snapshot.txt”), because the modified snapshot still references segment504and segment506, even if the modified snapshot no longer references segment508.

Furthermore, file references124have been updated to show that a separate container602, which corresponds to the modified writable snapshot (“snapshot.txt”), is referenced by the modified writable snapshot, because the modified snapshot now references a segment604within separate container602. Moreover, the instance of extent map212for the snapshot has also been modified to include a reference to segment604instead of a reference to segment508. As further shown inFIG. 6, extent map212also indicates that segment604is located within separate container602for the snapshot rather than original container502for the original target file. In other words, extent map212has been modified to indicate both (1) an additional deduplicated data segment that the snapshot newly references due to the modifying and (2) an additional deduplication container storing the additional deduplicated data segment (i.e., segment604) separate from an original deduplication container storing the deduplicated data segment (e.g., segment504) of the snapshot prior to the modifying.

As explained above in connection with method300inFIG. 3, the disclosed systems and methods may improve the speed of taking snapshots in deduplicated virtual file systems. Additionally, the disclosed systems and methods may prevent the degradation of performance of taking snapshots as the frequency of taking snapshots increases. Furthermore, the disclosed systems and methods may enable snapshots to be independent of each other such that modifying or deleting one snapshot does not necessarily impact another, as discussed further above.

The following provides a higher level overview of embodiments of the disclosed subject matter. During backup operations, a deduplicated virtual file system may be mounted to provide a backup destination (e.g., network file system destination) for a recovery manager (e.g., RMAN) to write control files, data files, transaction logs, archived logs, etc. Once a backup has completed, a snapshot is taken for the files created by the recovery manager. The deduplicated virtual file system may perform the following to complete a snapshot operation: (1) create a subdirectory with a snapshot ID as the directory name, (2) copy the head and map of the given set of files corresponding to the backup copy to the directory with the snapshot ID as its name, (3) generate and send file reference addition requests to deduplication storage for all files of the backup copy, and (4) deduplication storage will add file references to all referenced data segments. Once the backup snapshot is created, the recovery manager can perform a new backup to the backup destination with any file creation, update, deletion operation, etc. Any change will not impact existing backup snapshots.

During provisioning operations, a backup copy identified by a snapshot ID is chosen for provisioning. A provisioning operation performed by the deduplicated virtual file system has almost the same steps as creating a backup snapshot (with the exception, for example, that a backup snapshot is protected from modification whereas a provisioned snapshot is intended to be modifiable). Basically, (1) a new ID is generated to represent the provision copy and then a directory with the new ID as its name is created, (2) the head and the map of the backup copy are copied to the new ID directory, (3) file reference addition requests are generated and sent to the deduplication storage, and (4) segment references are added by the deduplication storage. After the snapshot has completed, the new writable snapshot may be mounted for test and development operations.

During test and development operations, file creation and deletion may introduce file reference additions and deletions to deduplication storage. File updates may introduce a file reference update request. The deduplication storage may dereference the old version of the file and add one or more references for the new version.

In summary, only a small amount of data including a copy of the metadata (e.g., metadata and/or extent map) and additional references, are needed to create a snapshot. This contrasts with systems that perform snapshots by reconstructing files from deduplicated segments and copying the reconstructed files. This also contrasts with systems that perform snapshots by copying deduplicated data segments. Instead, the disclosed systems and methods may simply copy the extent map that indicates how files may be reconstructed from the deduplicated data segments. Since the overhead of the deduplicated virtual file system snapshot operation is small, taking a snapshot is a very fast operation. Additionally, there may be no chain of relationship among snapshots. Accordingly, the performance of accessing snapshots does not degrade as the frequency of taking snapshots increases. Finally, each snapshot has its own references to segments (instead of snapshots sharing references to segments) and each snapshot can be removed without impacting any other snapshot. Moreover, the extent map may be implemented with a B+ tree that helps a storage system to quickly locate an extent with a given offset.

FIG. 7is a block diagram of an exemplary computing system710capable of implementing one or more of the embodiments described and/or illustrated herein. For example, all or a portion of computing system710may 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 inFIG. 3). All or a portion of computing system710may also perform and/or be a means for performing any other steps, methods, or processes described and/or illustrated herein.

Computing system710broadly represents any single or multi-processor computing device or system capable of executing computer-readable instructions. Examples of computing system710include, 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 system710may include at least one processor714and a system memory716.

Processor714generally represents any type or form of physical processing unit (e.g., a hardware-implemented central processing unit) capable of processing data or interpreting and executing instructions. In certain embodiments, processor714may receive instructions from a software application or module. These instructions may cause processor714to perform the functions of one or more of the exemplary embodiments described and/or illustrated herein.

System memory716generally 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 memory716include, 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 system710may include both a volatile memory unit (such as, for example, system memory716) and a non-volatile storage device (such as, for example, primary storage device732, as described in detail below). In one example, one or more of modules102fromFIG. 1may be loaded into system memory716.

In certain embodiments, exemplary computing system710may also include one or more components or elements in addition to processor714and system memory716. For example, as illustrated inFIG. 7, computing system710may include a memory controller718, an Input/Output (I/O) controller720, and a communication interface722, each of which may be interconnected via a communication infrastructure712. Communication infrastructure712generally represents any type or form of infrastructure capable of facilitating communication between one or more components of a computing device. Examples of communication infrastructure712include, 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 controller718generally represents any type or form of device capable of handling memory or data or controlling communication between one or more components of computing system710. For example, in certain embodiments memory controller718may control communication between processor714, system memory716, and I/O controller720via communication infrastructure712.

I/O controller720generally 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 controller720may control or facilitate transfer of data between one or more elements of computing system710, such as processor714, system memory716, communication interface722, display adapter726, input interface730, and storage interface734.

Communication interface722broadly represents any type or form of communication device or adapter capable of facilitating communication between exemplary computing system710and one or more additional devices. For example, in certain embodiments communication interface722may facilitate communication between computing system710and a private or public network including additional computing systems. Examples of communication interface722include, 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 interface722may provide a direct connection to a remote server via a direct link to a network, such as the Internet. Communication interface722may 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 interface722may also represent a host adapter configured to facilitate communication between computing system710and 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 interface722may also allow computing system710to engage in distributed or remote computing. For example, communication interface722may receive instructions from a remote device or send instructions to a remote device for execution.

As illustrated inFIG. 7, computing system710may also include at least one display device724coupled to communication infrastructure712via a display adapter726. Display device724generally represents any type or form of device capable of visually displaying information forwarded by display adapter726. Similarly, display adapter726generally represents any type or form of device configured to forward graphics, text, and other data from communication infrastructure712(or from a frame buffer, as known in the art) for display on display device724.

As illustrated inFIG. 7, exemplary computing system710may also include at least one input device728coupled to communication infrastructure712via an input interface730. Input device728generally represents any type or form of input device capable of providing input, either computer or human generated, to exemplary computing system710. Examples of input device728include, without limitation, a keyboard, a pointing device, a speech recognition device, or any other input device.

As illustrated inFIG. 7, exemplary computing system710may also include a primary storage device732and a backup storage device733coupled to communication infrastructure712via a storage interface734. Storage devices732and733generally represent any type or form of storage device or medium capable of storing data and/or other computer-readable instructions. For example, storage devices732and733may 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 interface734generally represents any type or form of interface or device for transferring data between storage devices732and733and other components of computing system710. In one example, database120fromFIG. 1may be stored in primary storage device732.

In certain embodiments, storage devices732and733may 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 devices732and733may also include other similar structures or devices for allowing computer software, data, or other computer-readable instructions to be loaded into computing system710. For example, storage devices732and733may be configured to read and write software, data, or other computer-readable information. Storage devices732and733may also be a part of computing system710or may be a separate device accessed through other interface systems.

The computer-readable medium containing the computer program may be loaded into computing system710. All or a portion of the computer program stored on the computer-readable medium may then be stored in system memory716and/or various portions of storage devices732and733. When executed by processor714, a computer program loaded into computing system710may cause processor714to 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 system710may be configured as an Application Specific Integrated Circuit (ASIC) adapted to implement one or more of the exemplary embodiments disclosed herein.

FIG. 8is a block diagram of an exemplary network architecture800in which client systems810,820, and830and servers840and845may be coupled to a network850. As detailed above, all or a portion of network architecture800may 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 inFIG. 3). All or a portion of network architecture800may also be used to perform and/or be a means for performing other steps and features set forth in the instant disclosure.

Client systems810,820, and830generally represent any type or form of computing device or system, such as exemplary computing system710inFIG. 7. Similarly, servers840and845generally represent computing devices or systems, such as application servers or database servers, configured to provide various database services and/or run certain software applications. Network850generally represents any telecommunication or computer network including, for example, an intranet, a WAN, a LAN, a PAN, or the Internet. In one example, client systems810,820, and/or830and/or servers840and/or845may include all or a portion of system100fromFIG. 1.

As illustrated inFIG. 8, one or more storage devices860(1)-(N) may be directly attached to server840. Similarly, one or more storage devices870(1)-(N) may be directly attached to server845. Storage devices860(1)-(N) and storage devices870(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 devices860(1)-(N) and storage devices870(1)-(N) may represent Network-Attached Storage (NAS) devices configured to communicate with servers840and845using various protocols, such as Network File System (NFS), Server Message Block (SMB), or Common Internet File System (CIFS).

Servers840and845may also be connected to a Storage Area Network (SAN) fabric880. SAN fabric880generally represents any type or form of computer network or architecture capable of facilitating communication between a plurality of storage devices. SAN fabric880may facilitate communication between servers840and845and a plurality of storage devices890(1)-(N) and/or an intelligent storage array895. SAN fabric880may also facilitate, via network850and servers840and845, communication between client systems810,820, and830and storage devices890(1)-(N) and/or intelligent storage array895in such a manner that devices890(1)-(N) and array895appear as locally attached devices to client systems810,820, and830. As with storage devices860(1)-(N) and storage devices870(1)-(N), storage devices890(1)-(N) and intelligent storage array895generally 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 system710ofFIG. 7, a communication interface, such as communication interface722inFIG. 7, may be used to provide connectivity between each client system810,820, and830and network850. Client systems810,820, and830may be able to access information on server840or845using, for example, a web browser or other client software. Such software may allow client systems810,820, and830to access data hosted by server840, server845, storage devices860(1)-(N), storage devices870(1)-(N), storage devices890(1)-(N), or intelligent storage array895. AlthoughFIG. 8depicts 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 server840, server845, storage devices860(1)-(N), storage devices870(1)-(N), storage devices890(1)-(N), intelligent storage array895, 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 server840, run by server845, and distributed to client systems810,820, and830over network850.

As detailed above, computing system710and/or one or more components of network architecture800may 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 taking snapshots in a deduplicated virtual file system.