Patent Application
20130218847
The present invention relates to a file server apparatus, an information system, and a method for controlling the file server apparatus.
PTL 1 discloses a technique for a distributed file system in which files are distributed and stored in a plurality of file servers. When data is stored redundantly, this technique eliminates data duplication while suppressing the loads on file servers. More specifically, in a storage system including a metadata server and a storage server, files stored in the storage system are classified into groups, the metadata server instructs the storage server storing the files in a distributed manner to detect duplication of files and to eliminate the duplicate data, and the storage server detects duplicate data by comparing segments of files stored therein to each other and deletes the detected duplicate data from the storage server.
PTL 2 discloses a computer system including a computer and a storage apparatus and configured to perform data de-duplication as follows. Specifically, in order to avoid load concentration to a volume under heavy load in the de-duplication, the computer determines files of a same content stored in duplicate in a plurality of volumes as consolidation target files, identifies plurality of volumes storing the consolidation target files, selects at least one volume from the plurality of volumes as a consolidation volume based on the load of the identified plurality of volumes, and deletes the consolidation target files stored in the volumes not selected.
When duplicate files are consolidated into a specific file for data de-duplication as described in PTL 2, the consolidation file, i.e., the specific file is accessed frequently due to accesses to individual files, whereby load is concentrated to a volume storing the consolidation file.
Possible solutions to such problem of load concentration to a specific file are, for example, to provide a plurality of specific files for access distribution and to store the specific file into a volume under low load or a volume achieving high performance.
However, since the contents of files vary as time passes by, such measures provide effects of the load balancing just temporarily. Therefore, in order to sustain effects of the load distribution, an appropriate measure must be taken by considering temporal changes of file contents.
In view of such problems, it is a primary object of the present invention to provide a file server apparatus, an information system and a method for controlling the file server apparatus, which are capable of stably providing effects of load balancing.
According to one aspect of the present invention for achieving the above object, provided is a file server apparatus that processes files stored in a plurality of volumes of a storage apparatus in response to an I/O request sent from a client apparatus including, when entity data of a plurality of files has a common portion, a unit that generates a consolidation file that holds common entity data as consolidated data, and a unit that manages each of the plurality of files as a de-duplication file that does not hold the consolidated data, and, when there is the I/O request to at least one of the plurality of files, acquires the consolidated data and processes in response to the I/O request to at least one of the plurality of files, and holds difference data generated by performing processing in response to the I/O request including referring to the consolidation file, wherein whenever a predetermined timing comes, the file server apparatus determines a load balancing method according to a dependency obtained, for each of the de-duplication files, from a ratio of a data amount of the difference data of each of the de-duplication file with respect to a data amount of the consolidated data, and distributes at least any one of the consolidated data, the difference data and data of a non de-duplication file into the plurality of volumes in accordance with the determined load balancing method, the non de-duplication file being a file other than the de-duplication files and the consolidation file.
Other problems and solutions thereto disclosed by the present invention will be clarified by the following description of embodiments of the present invention with reference to the accompanying drawings.
The present invention provides effects of load balancing in a stable manner.
Hereinafter, embodiments of the present invention are described with reference to the accompanying drawings.
The client apparatus 2, the metadata server apparatus 3 and the file server apparatus 4 are coupled in a manner enabling mutual communication to each other via a first communication network 5. The metadata server apparatus 3, the file server apparatus 4 and the storage apparatus 10 are coupled to each other in a such manner enabling mutual communication other via a first communication network 6.
The first communication network 5 is, for example, LAN, WAN, internet, a lease line, a public telecommunication network, or the like. A second communication network 51 is, for example, SAN (Storage Area Network), LAN, WAN, internet, or the like.
The client apparatus 2 is, for example, an information system which provides bank's automatic cash dispenser service, internet web page browsing service, or the like, such as, for example, a personal computer, an office computer, a main frame, and the like.
The client apparatus 2 includes a central processing unit 21, an auxiliary storage apparatus 22 and a network interface (hereinafter, referred to as a network I/F 23). The central processing unit 21 comprises, for example, a CPU or a MPU. The storage apparatus 22 is a volatile or nonvolatile memory 22 (RAM, ROM, NVRAM (Non Volatile RAM)), a hard disk drive, SSD (Solid State Drive), and the like. The client apparatus 2 may further include an input device (keyboard, mouse, touch panel, or the like), and an output device (liquid crystal display, printer, or the like).
Both the metadata server apparatus 3 and the file server apparatus 4 (hereinafter, these servers may be collectively called as a server apparatus) are an information system which provides a file utilization environment to the client apparatus 2 by using a storage area provided by the storage apparatus 10, such as, for example, a personal computer, an office computer, a main frame, or the like. The metadata server apparatus 3 provides metadata described later to the client apparatus 2, and the file storage apparatus 4 provides entity data described later to the client apparatus 2.
Server apparatuses 3, 4 include central processing units 31, 41, storage devices 32, 42, first network interfaces (hereinafter, referred to as first network I/F 33, 43), and second network interfaces (hereinafter, referred to as second I/F 34, 44).
Central processing units 31, 41 are configured by using, for example, CPU or MPU. Storage devices 32, 42 are, for example, volatile or nonvolatile memory 22 (RAM, ROM, NVRAM), a hard disk drive, SSD, or the like. First network I/F 33, 43 is, for example, NIC (Network Interface Card), HBA (Host Bus Adaptor), or the like.
The storage apparatus 10 provides a data storage area to server apparatuses 3, 4. The storage apparatus 10 is, for example, a disk array device.
The storage apparatus 10 includes one or more communication control units 11, one or more data controllers 12, one or more drive control units 13, a cache memory 14, a shared memory 15, a maintenance device 18, and one or more storage drives 17. The communication control unit 11, the data controller 12, the drive control unit 13, the cache memory 14 and the shared memory 15 are coupled to each other in a manner enabling mutual communication via an internal switch 16. The storage drive 17 may be accommodated in a housing separately from other components of the storage apparatus 10.
The communication control unit 11 communicates with server apparatuses 3, 4 via the first communication network 6. The first communication control unit 11 includes a central processing unit, a memory and a network interface. The communication control unit 11 controls, for example, communication between server apparatuses 3, 4 performed according to a communication protocol and I/O request (data write request and data read request) received from server apparatuses 3, 4.
The drive control unit 13 communicates with the storage drive 17. The drive control unit 13 includes a central processing unit, a memory and a network interface. The drive control unit 13 performs, for example, reading of data stored in the storage drive 17, transfer of the read data to the cache memory 14, and transfer of data stored in the cache memory 14 to the storage drive 17.
The data controller 12 mediates data transfer among the communication control unit 11, the drive control unit 13 and the cache memory 14. The data controller 12 includes a central processing unit, a data transfer device such as DMA (Direct Memory Access), a memory and a network interface.
The data controller 12 performs, for example, delivery of data (data read from the storage drive 17 and data written into the storage drive 17) between the communication unit 11 and the drive control part 12, performed via the cache memory 14, staging (read of data from the storage drive 17) of data stored in the cache memory 14, and de-staging (writing of data into the storage drive 17).
The cache memory 14 temporarily stores, for example, data to be written into the storage drive 17 and data read from the storage drive 17 and sent to server apparatuses 3, 4. The cache memory 14 is configured by using, for example, a RAM.
The shared memory 14 stores, for example, programs and data used by the communication control unit 11, the drive control unit 13, and the data controller 12. The shared memory 15 is configured by using, for example, a storage element such as a RAM, ROM, NVRAM, and the like.
The maintenance device 18 performs setting, control, status monitoring or the like of components of the storage apparatus 10. The maintenance device 18 is an information device including a central processing unit, a memory, an auxiliary storage device, an input device, a display device, a network interface, and the like.
The maintenance device 18 communicates with components of the storage apparatus 10 via a communication means such as LAN from time to time to perform acquisition of information (configuration information, various setting information, usage information, and the like) relating to the storage apparatus 10, and setting, control, maintenance and the like of the storage apparatus 10.
The maintenance device 18 may be, in some cases, communicatively coupled with an information apparatus (herein referred to as the management apparatus) provided outside the storage apparatus 10 via a communication means such as a LAN. The management apparatus provides the user and operator with an interface (such as GUI (Graphical User Interface), CLI (Command Line Interface), and the like) for setting, control, maintenance, and the like (including software introduction and updating) of the storage apparatus 10.
The storage drive 17 is, for example, a hard disk drive (such as SAS (Serial Attached SCSI), SATA (Serial ATA), FC (Fibre Channel), PATA (Parallel ATA), SCSI (Small Computer System Interface), and the like) and a semiconductor storage device (SSD), or the like.
The storage apparatus 10 provides a storage location of data to server apparatuses 3, 4 on the basis of a logical storage area (hereinafter, alternatively referred to as LU171 (LU: Logical Unit) provided by controlling the storage drive 17 by a RAID (Redundant Arrays of Inexpensive (or Independent) Disks) method (for example, RAID 0 to 6). The logical storage area is provided, for example, as a storage area of a RAID group (alternatively referred to as a parity group).
The storage apparatus 10, when receiving an I/O request sent from server apparatuses 3, 4, operates, for example, as follows:
For example, when the storage apparatus 10 receives, for example, a data write request from server apparatuses 3, 4, the communication control unit 11 notifies the reception thereof to the data controller 12. Upon receiving the notification, the data controller 12 generates a drive write request based on the above data write request, sends the drive write request to the drive control unit 13 and stores the write data into the cache memory 14 as well. When the data controller 12 stores the write data into the cache memory 14, the communication control unit 11 sends a completion report to server apparatuses 3, 4.
Upon receiving the drive write request from the data controller 12, the drive control unit 13 registers the received drive write request to a write process queue. Then, the drive control unit 13 reads the drive write request from the write process queue from time to time, reads write data specified in the read drive write request from the cache memory 14, and writes the read write data into the storage drive 17.
When the storage apparatus 10 receives, for example, a data read request from server apparatuses 3, 4, the communication control unit 11 notifies the reception thereof to the drive control unit 13. Upon receiving the notification, the drive control unit 13 reads data specified in the data read request (for example, data specified by LBA (Logical Block Address)) from the storage drive 17. If read data has already been read out to the cache memory 14, reading of data from the storage drive 17 may be omitted.
The data controller 12 reads data read by the drive control unit 13 from the cache memory 14 and transfers the read data to the communication control unit 11. Upon receiving the read data sent from the data controller 12, the communication control unit 11 transfers the read data to server apparatuses 3, 4.
<Description of Functions>
The client apparatus 2 includes an application 211, a file sharing processing unit 212, a file system 213, and a kernel/driver 214. The application 211 is implemented by a program which implements information processing service in the client apparatus 2. The application 211 provides, for example, functions relating to a bank's automatic cash dispenser service or internet web page browsing service.
The file sharing processing unit 212 provides, in cooperation with file sharing processing units 311, 411 of server apparatuses 3, 4, a file sharing environment to the application 211 between server apparatuses 3, 4. The file sharing processing units 311, 411 will be described later. The file sharing processing unit 311 is implemented by using, for example, such as NFS (Network File System), CIFS (Common Internet File System), AFS (Andrew File System), or the like.
The file system 213 implements a file utilization environment on file basis or directory basis. The file system 213 is implemented by using, for example, FAT (File Allocation Table), NTFS, HFS (Hierarchical File System), ext2 (second extended file system), ext3 (third extended file system), ext4 (fourth extended file system), UDF (Universal Disk Format), HPFS (High Performance File system), JFS (Journaled File System), UFS (Unix File System), VTOC (Volume Table Of Contents), XFS, or the like.
The kernel/driver 214 is implemented, for example, by executing a kernel module or a driver module of an operating system. The kernel module includes, for example, programs for implementing process controls in the client apparatus 2 (execution management, scheduling, management of storage areas utilized by processes, handling with respect to interrupt requests, and the like). The driver module includes, for example, programs for implementing control of hardware and peripheral devices provided with the client apparatus 2.
As shown in
File sharing processing units 311, 411 provide, in cooperation with file sharing processing units 311, 411 of other server apparatuses 3, 4 or a file sharing processing unit 212 of the client apparatus 2, a file sharing environment between server apparatuses 3, 4 to the client apparatus 2.
The data migration processing units 312, 412 perform data migration processing between file server apparatuses 4. Details of the data migration processing performed between file server apparatuses 4 are described later.
File systems 313, 413 implement a data utilization environment on file basis or directory basis to the client apparatus 2. File systems 313, 413 are implemented, for example, by using FAT, NTFS, HFS, ext2, ext3, ext4, UDF, HPFS, JFS, UFS, VTOC, XFS, or the like.
Logical path management processing units 314, 414 manage paths (hereinafter, referred to as a logical path) of data including an I/O request and a response thereof generated when the client apparatus 2 accesses to LU 171. Logical path management processing units 314, 414 also serve as a load balancer which distributes I/O requests to logical paths so as to balance the load applied to logical paths.
Individual logical paths are identified, for example, with a combination of at least two selected from a group consisting of a communication port of first network I/F 33, 43 of server apparatuses 3, 4, a communication port of second network I/F 34, 44 of server apparatuses 3, 4, a communication port of a communication device (router, switching hub, or the like) configuring the first communication network 6, a communication port of the communication control unit 11 of the storage apparatus 10, and LU 171 at an access destination.
Logical path management processing units 314, 414 perform, for example, load balancing among logical paths by allocating an I/O request sent from the client apparatus 2 to logical paths by round-robin scheduling. Further, logical path management processing units 314, 414 perform the load balancing among logical paths by dynamically distributing I/O requests sent from the client apparatus 2 to the logical paths according to the load of the logical paths (for example, the number of I/O requests or the amount of data flowing per unit time.)
Kernel/driver 315, 415 are implemented, for example, by executing a kernel module or a driver module of an operating system. The kernel module includes, for example, programs for implementing process control in server apparatuses 3, 4. The driver module includes, for example, programs for implementing control of hardware and peripheral devices provided with server apparatuses 3, 4.
Next, file systems 313, 413 of server apparatuses 3, 4 are described.
Super block 51 contains settings of the number of data blocks, the size of a unit data block and the number of empty data blocks which can be handled by file systems 313, 413, and the number of inodes, the remaining number of inodes, or the like which are held by file systems 313, 413 as a whole. File systems 313, 413 manage files by associating one inode with one file (or directory).
The inode management table 52 stores an inode (or directory entry (including an inode which contains information relating to the directory only)) of a file (or a directory) stored in LU 171. The data block 53 stores entity data, which will be described later.
File systems 313, 413 access to a file with reference to a directory entry. For example, as shown in
In the information system 1, load applied to server apparatuses 3, 4 when a client apparatus 2 accesses to a file is balanced by making an apparatus (metadata server apparatus 3) providing the metadata to the client apparatus 2 and an apparatus (file server apparatus 4) providing the entity data to the client apparatus 2 independent from each other. For this reason, the inode management table 52 managed by the metadata server apparatus 3 contains information for identifying the location of the entity data corresponding to the metadata.
<Basic Operations>
Next, basic operations of the information system 1 are described.
Basic operations of the information system 1 when a client apparatus 2 accesses to a file stored in the storage apparatus 10 are described with reference to a flowchart shown in
When the application 211 of the client apparatus 2 activates a processing (reference, updating, duplication, deletion, or the like) with respect to a file managed by the storage apparatus 10, the client apparatus 2 sends an acquisition request of the metadata of a file to be processed (hereinafter, referred to as a target file) to the metadata server apparatus 3 (S711).
Upon receiving the above acquisition request (S712), the metadata server apparatus 3 acquires the metadata of the target file from the storage apparatus 10 (S713) and sends the acquired metadata to the client apparatus 2 (S714).
Upon receiving the metadata of the target file from the metadata server apparatus 3 (S715), the client apparatus 2 acquires the location of the entity data from the metadata (S716) and sends a processing request with respect to the entity data of the target file to a file server apparatus 4 which manages the entity data (S717).
Upon receiving the above processing request (S718), the file server apparatus 4 performs a processing (hereinafter, referred to as a file I/O processing) according to the processing request (S719) and sends a result thereof (hereinafter, referred to as a processing result) to the client apparatus 2 and the metadata server apparatus 3 (S720). Details of the file I/O processing S719 will be described later.
The processing result received by the client apparatus 2 is passed to the application 11 of the client apparatus 2 (S721).
Upon receiving the above processing result (S722), the metadata server apparatus 3 updates the metadata of the target file on the basis of the received processing result (S723).
<De-Duplication>
The file server apparatus 4 includes a scheme which eliminates duplicate holdings of common parts of the entity data when each entity data of a plurality of files has common parts. Hereinafter, the scheme is called a de-duplication function, and eliminating duplicate holdings of common parts of entity data is called a de-duplication.
The de-duplication is performed in such a manner as described below. For example, when there are three files “File 1”, “File 2” and “File 3”, as shown in
In the case of
When the file I/O processing S719 described above is executed by targeting de-duplication files and thereby a change occurs in contents of the entity data as illustrated in
<File I/O Processing>
As shown in
If the received processing request is “Update”, the file server apparatus 4 firstly determines whether or not the target file is a de-duplication file (S1212). If the target file is determined as not a de-duplication file (S1212: NO), the process proceeds to S1213. If the target file is determined as a de-duplication file (S1212: YES), the process proceeds to S1216.
At S1213, the file server apparatus 4 acquires entity data of the target file. Then, the file server apparatus 4 performs an updating processing specified in the processing request with respect to entity data of the target file (S1214) and updates metadata of the target file to updated contents (S1215). Thereafter, the process proceeds to S720 shown in
In the aforementioned processing at S723, updating of metadata same as updating of metadata at S215 is also performed in the metadata server apparatus 3, whereby contents of metadata managed by the metadata server apparatus 3 and contents of metadata managed by the file server apparatus 4 are synchronized with each other.
On the other hand, at S1216, the file server apparatus 4 acquires consolidated data of the target file and difference data of the target file and combines these data to generate entity data of the target file. Then, the file server apparatus 4 performs update processing specified in the processing request with respect to the generated entity data and stores difference data between the consolidated data of the target file and entity data of the target file after update (S1217) to update metadata of the target file to updated contents (S1218). Thereafter, the process proceeds to S720 shown in
When the processing request received at S1211 is “Reference”, the file server apparatus 4 determines whether or not the target file is a de-duplication file (S1221). If the target file is not a de-duplication file (S1221: NO), the process proceeds to S1222. If the target file is a de-duplication file (S1221: YES), the process proceeds to S1223.
At S1222, the file server apparatus 4 acquires entity data of the target file. Thereafter, the process proceeds to S720.
At S1223, the file server apparatus 4 acquires consolidated data and difference data of the target file and generates entity data by combining the two data. Thereafter, the process proceeds to S720 of
At S1311 of
At S1312, the file server apparatus 4 determines whether or not the target file is a de-duplication file. If the target file is not a de-duplication file (S1312: NO), the process proceeds to S1313. If the target file is a de-duplication file (S1312: YES), the process proceeds to S1314.
If the process proceeds to S1313, the file server apparatus 4 deletes metadata of the target file (for example, by disabling an inode management table 52 of the target file). Thereafter, the process proceeds to S720 of
On the other hand, if the process proceeds to S1314, the file server apparatus 4 firstly deletes metadata of the target file (for example, by disabling an inode management table 52 of the target file) and decrements (−1) a value of a reference counter 563 of the consolidation file to which the target file refers (S1315). If the value of the reference counter 563 becomes 0 as a result of the subtraction, the file server apparatus 4 deletes metadata of the consolidation file (for example, by disabling the inode management table 52 of the consolidation file (S1316). Thereafter, the process proceeds to S720 of
At S1411 of
At S1412, the file server apparatus 4 determines whether or not a consolidation file whose consolidated data matches entity data of the target file exists. If no consolidation file whose consolidated data matches entity data of the target file exists (S1412: NO), the process proceeds to S1413. If such a consolidation file exists (S1412: YES), the process proceeds to S1415.
At S1413, the file server apparatus 4 newly generates a consolidation file comprising metadata of the target file as metadata (however, a new inode number 521 is acquired) and entity data of the target file as consolidated data (implementation of de-duplication).
At S1415, the file server apparatus 4 sets the inode number of the consolidation file retrieved at S1412 or the inode number of the consolidation file generated at S1413 to metadata of the target file.
Then, the file server apparatus 4 deletes entity data of the target file (S1416) and increments (+1) the reference counter 563 of the consolidation file (S1417). Thus, the target file turns to a de-duplication file.
Next, the file server apparatus 4 generates a duplication destination file as the de-duplication file by generating metadata of the duplication destination file (S1418) and increments (+1) the reference counter 563 of the consolidation file (S1419). As shown in
In the meantime, if an appropriate directory structure for storing consolidation files is worked out, the retrieval efficiency in determining at S1412 whether or not a consolidation file having entity data matching entity data of the target file already exists can be improved.
With such configuration of the directory structure, consolidation files for comparison can be sorted out on the basis of the data size of the target file, whereby retrieval efficiency in determining at S1412 whether or not a consolidation file having entity data matching entity data of the target file already exists can be improved. Further, troubles such as loss of a consolidation file due to an operation error by a user may be prevented by setting an appropriate access right to the above dedicated parent directory.
<Function of Allocating Files Among File Server Apparatuses>
The information system 1 has a function with which a group of de-duplication files including a consolidation file of consolidated data and a group of de-duplication files referring to the consolidation file are allocated to file server apparatuses 4 according to a ratio of difference data to the consolidated data (hereinafter, referred to as a dependency). Hereinafter, this function (hereinafter, referred to as a file allocating function) is described.
Allocation of the group of de-duplication files among file server apparatuses 4 according to a dependency thus determined is performed, for example, as follows:
Each of file server apparatuses 4 determines a dependency of the consolidation file allocated thereto, compares the determined dependency with a predetermined policy to determine file server apparatuses 4 to which the group of de-duplication files are to be allocated (destined), and sends result thereof (hereinafter, referred to as a determination result) to the metadata server apparatus 3.
Upon receiving the determination result from the file server apparatus 4, the metadata server apparatus 3 allocates (migrates) the group of de-duplication files to file server apparatuses 4 according to the determination result.
The migration destination determination table 2100 shown in
In the description given hereinafter, a dependency within a range of “0.7” exclusive to “1.0” inclusive is referred to as an initial stage (first range), a dependency within a range of “0.2” exclusive to “0.7” inclusive is referred to as a medium stage (second range), and a dependency range of “0.0” and “0.2”, both inclusive, is referred to as a later stage (third range). Each of the dependency ranges at initial, medium and later stages is not limited thereto. The dependency ranges may be set appropriately by a user or an operator according to the specifications or performance of the information system 1 or requirements for the information system 1.
The file server apparatus 4 monitors in real time for the coming of a timing (periodically, at a pre-scheduled date/time, or the like) to send the above determination result to the metadata server apparatus 3 (S2311). When the timing comes (S2311: YES), the file server apparatus 4 determines the dependency (mean value of dependencies) of consolidation files (de-duplication files) allocated thereto (S2312).
Next, the file server apparatus 4 compares a determined dependency with the migration destination determination table 2100 to determine the migration destination of the group of de-duplication files allocated thereto (S2313). Then, the file server apparatus 4 sends the result (hereinafter, referred to as a determination result) to the metadata server apparatus 3 (S2314).
The metadata server apparatus 3 is in standby in real time for reception of the above determination result (S2321). Upon receiving the above determination result (S2321: YES), the metadata server apparatus 3 communicates with a file server apparatus 4 of the migration source to acquire the group of de-duplication files to be migrated and deletes those group of de-duplication files from the file server apparatus 4 of the migration source (S2322).
Next, the metadata server apparatus 3 communicates with a file server apparatus 4 of the migration destination to transfer and allocate acquired group of de-duplication files to the file server apparatus 4 of the migration destination (S2323). The metadata server apparatus 3 updates an entity management device 551 and an entity storage position 552 in an inode management table 52 of the group of de-duplication files migrated from the source to the destination (S2324).
The migration processing 2300 described above migrates the group of de-duplication files among file server apparatuses 4 via the metadata server apparatus 3, but the group of de-duplication files may also be migrated by direct communication among file server apparatuses 4.
<Load Balancing Function in File Server Apparatus>
The file server apparatus 4 has a scheme capable of performing the load balancing by appropriately allocating data of files allocated thereto into LU 171 serving as a storage area thereof. The file server apparatus 4 performs the load balancing by selecting any one of the three load balancing methods (Method A, Method B and Method C).
When performing the load balancing in accordance with Method A among the three load balancing methods, the file server apparatus 4 allocates a consolidation file to a plurality of LUs 171.
Method A is effective when mainly the group of de-duplication files of the dependency at the initial stage is allocated to the file server apparatus 4 by the file al-locating function among file server apparatuses 4. That is, when the group of de-duplication files of the dependency at the initial stage is allocated to the file server apparatus 4, access to a consolidation file takes place frequently due to access to individual de-duplication files of a group of de-duplication files of the dependency at the initial stage. Loads resulting from accesses to de-duplication files can be distributed to plurality of LUs 171 by implementing Method A which distributes a consolidation file to the plurality of LUs 171.
In
“FS1” communicates with the client apparatus 2, the metadata server apparatus 3 and other file server apparatuses 4 to serve as a contact window thereof for utilizing storage areas provided by the three file systems 413 including “FS11”, “FS12” and “FS13”.
When performing the load balancing by Method B, the file server apparatus 4 distributes difference data of the de-duplication files to a plurality of LUs 171.
Method B is effective when mainly the group of de-duplication files of the dependency at the medium stage is allocated to file server apparatus 4 by the file al-locating function among file server apparatuses 4. That is, when the group of de-duplication files of the dependency at the medium stage is allocated to the file server apparatus 4, access to difference data takes place frequently due to access to de-duplication files of a group of de-duplication files of the dependency at the medium stage. Loads resulting from accesses to de-duplication files can be distributed to a plurality of LUs 171 by implementing Method B which distributes difference data to the plurality of LUs 171.
In
“FS2” communicates with the client apparatus 2, the metadata server apparatus 3 and other file server apparatuses 4 to serve as a contact window thereof for utilizing storage areas provided by the three file systems 413 including “FS21”, “FS22” and “FS23”.
In
When performing the load balancing by Method C, the file server apparatus 4 stubs a file which is neither a de-duplication file nor a consolidation file (hereinafter, referred to as a non de-duplication file), among LUs 171 to which the group of de-duplication files are allocated, and allocates the entity data of non de-duplication files to another LU 171. For the group of de-duplication files of a lower dependency, the de-duplication is implemented again (hereinafter, referred to as a re-deduplication).
Method C is effective when mainly the group of de-duplication files of the dependency at the later stage is allocated to file server apparatus 4 by the above file al-locating function among file server apparatuses 4. That is, when the group of de-duplication files of the dependency at the later stage is allocated to file server apparatus 4, access to difference data takes place frequently due to access to de-duplication files of a group of de-duplication files of the dependency at the later stage. However, load to LU 171 to which a group of de-duplication files is allocated is reduced by performing Method C which stubs non de-duplication files and allocates entity data of the non de-duplication files to LU 171 different from LU 171 to which a group of de-duplication files is allocated. Further, if the dependency increases by the re-deduplication, load to LU 171 of the file server apparatus 4 is reduced by applying another load balancing method.
In
“FS3” communicates with the client apparatus 2, the metadata server apparatus 3 and other file server apparatuses 4 to serve as a contact window thereof for utilizing storage areas provided by the three file systems 413 including “FS31”, “FS32” and “FS33”.
When effect of the load balancing is not sufficient even after stubbing of non deduplication files and the re-deduplication, for example, de-duplication files may be stubbed to allocate entity data thereof to a plurality of LUs 171.
In
The file server apparatus 4, for example, determines in the following manner whether or not the re-deduplication is necessary, and performs the re-deduplication if its necessity is determined.
Specifically, as shown in
Next, the file server apparatus 4 compares a total number of reference data blocks of current de-duplication files with respect to a present consolidation file (hereinafter, referred to as a present reference number) and a total number of reference data blocks of current de-duplication files with respect to a temporary consolidation file (hereinafter, referred to as a temporary reference number) with each other, and if the temporary reference number exceeds the present reference number, the file server apparatus 4 determines that re-deduplication is necessary (implementation of the re-deduplication is enabled).
Then, the file server apparatus 4 generates difference data by comparing the temporary consolidation file and de-duplication files with each other, for example, as shown in
The file server apparatus 4 monitors in real time for the coming of a timing (periodically, at a pre-scheduled time, or the like) to implement the load balancing (S3111). When the timing to implement the load balancing has come (S3111: YES), the file server apparatus 4 determines a method of the load balancing to be implemented (S3112). The determination is made by referring to pre-stored tables.
Of the tables, a load balancing method determination table 3200 shown in
On the other hand, a load balancing method determination table 3300 shown in
Back to
First, the file server apparatus 4 selects a consolidation file allocated thereto (S3411) and acquires information (the number of de-duplication files referring to the selected consolidation file (hereinafter, referred to as a selected consolidation file), access frequency to the consolidation file, and the like) relating to the selected consolidation file (S3412).
Next, the file server apparatus 4 determines based on the acquired information whether or not the load balancing of the selected consolidation file is necessary (S3413). This determination is made, for example, by checking whether or not the number of de-duplication files referring to the selected consolidation file and access frequency to the selected consolidation file exceed predetermined thresholds. If determined that the load balancing is necessary (S3413: YES), the process proceeds to S3414, and if determined that the load balancing is not necessary (S3413: NO), the process proceeds to S3421.
At S3414, the file server apparatus 4 determines the other file system 413 as a duplication destination of the selected consolidation file. The file server apparatus 4 selects a file system 413 as a duplication destination in such a manner that the load balancing functions efficiently (for example, in such a manner that the consolidation file is allocated evenly to respective file systems 413).
As a method for selecting a file system 413 as a migration destination of the selected consolidation file at this stage, there is, for example, a method which assigns sequential identifiers to respective file systems 413 which are selectable as the duplication destination and selects a file system 413 assigned an identifier corresponding to a remainder obtained by dividing an inode number of the selected consolidation file by a total number of file systems 413, as a duplication destination.
Next, the file server apparatus 4 duplicates the selected consolidation file into a determined duplication destination (S3415) and modifies the content of the inode management table 52 of the consolidation file (consolidation file inode number 561) of de-duplication files referring to the selected consolidation file (S3416). Further, the file server apparatus 4 stores, in a table, a relation between the selected consolidation file and a selected consolidation file duplicated into the duplication destination. Thereafter, the process proceeds to S3431.
Back to
At S3431, the file server apparatus 4 determines whether or not another consolidation file to be selected exists. If determined that such a consolidation file exists (S3431: YES), the process returns to S3411. If no other consolidation file exists (S3431: NO), the process returns to S3211 of
In this way, when the dependencies of de-duplication files are high and thereby access load to a consolidation file is high, the file server apparatus 4 aggressively distributes the consolidated data to different LUs 171 (file system 413), thereby preventing load concentration to a specific LU 171.
First, the file server apparatus 4 selects a consolidation file allocated thereto (S3611) and acquires information (such as, access frequency to selected de-duplication files) of de-duplication files referring to the selected consolidation file (hereinafter, referred to as a selected de-duplication file) (S3612).
Next, the file server apparatus 4 determines based on the acquired information whether or not the load balancing of the selected de-duplication file is necessary (S3613). This determination is made, for example, by checking whether or not access frequency to the selected de-duplication file exceeds a predetermined threshold. If determined that the load balancing is necessary (S3613: YES), the process proceeds to S3614, and if determined that the load balancing is not necessary (S3613: NO), the process proceeds to S3621.
At S3614, the file server apparatus 4 determines a file system 413 as a migration destination of the selected de-duplication file (of difference data). The file server apparatus 4 selects a file system 413 as a migration destination of the selected deduplication file in such a manner that the load balancing functions efficiently (for example, in such a manner that the selected de-duplication file is allocated evenly to respective file systems 413).
As a method for selecting a file system 413 as a migration destination of the selected de-duplication file at this stage, there is a method which assigns sequential identifiers to respective file systems 413 which are selectable as the duplication destination and selects a file system 413 assigned an identifier corresponding to a balance obtained by dividing an inode number of the selected de-duplication file by a total number of file systems 413, as a duplication destination.
Next, the file server apparatus 4 generates an inode information of the selected deduplication file at the determined migration destination and moves difference data of the selected de-duplication file to the migration destination (S3615). Further, the file server apparatus 4 sets the location (identifier of the file system 413 of the migration destination, inode number of the migration destination, and the like) of difference data moved to the migration destination to a stub (metadata) of the migration source (S3616). Thereafter, the process proceeds to S3631.
At S3621, the file server apparatus 4 determines with reference to the stub of the migration source whether or not the selected de-duplication file exists in another file system 413. If determined that the selected de-duplication file exists, the file server apparatus 4 moves difference data of the selected de-duplication file from the other file system 413 to the migration source and deletes inode information and difference data of the selected de-duplication file from the other file system 413. Then, the file server apparatus 4 sets the location of difference data moved to the migration source to the metadata of the migration source (S3622).
At S3631, the file server apparatus 4 determines whether or not a consolidation file to be selected exists. If the consolidation file exists (S3631: YES), the process returns to S3611. If no such consolidation file exists (S3631: NO), the process returns to S3211 of
In this way, when the dependency of de-duplication files is approximately medium and thereby access load to a de-duplication file becomes high, the file server apparatus 4 aggressively distributes difference data to different LUs 171 (file system 413), thereby preventing load concentration to a specific LU 171.
As shown in
Next, the file server apparatus 4 determines based on the acquired information whether or not the load balancing of the selected non de-duplication file is necessary (S3713). This determination is made by checking whether or not the access frequency of the selected non de-duplication file exceeds a predetermined threshold. If determined that the load balancing is necessary (S3713: YES), the process proceeds to S3714, and if determined that the load balancing is not necessary (S3713: NO), the process proceeds to S3721.
At S3714, the file server apparatus 4 determines another file system 413 as a migration destination of the selected non de-duplication file. The file server apparatus 4 selects a file system 413 as a migration destination of the selected non de-duplication file in such a manner that the load balancing functions efficiently (for example, in such a manner that the selected non de-duplication file is allocated evenly to respective file systems 413).
As a method for selecting a file system 413 as a migration destination of the selected non de-duplication file, there is such as a method which assigns sequential identifiers to respective file systems 413 which are selectable as the migration destination and selects a file system 413 assigned an identifier corresponding to a remainder obtained by dividing the inode number of the selected non de-duplication file by a total number of file systems 413, as a duplication destination.
Next, the file server apparatus 4 generates inode information of the selected non deduplication file at a determined migration destination, sets the location (identifier of a file system 413 of the migration destination, inode number of the migration destination, and the like) of difference data moved to the migration destination to the metadata (stub) of the migration source, and stubs the selected non de-duplication file by moving entity data of the selected non de-duplication file to the migration destination (S3715). Thereafter, the process proceeds to S3731.
On the other hand, the file server apparatus 4 determines with reference to the stub of the migration source whether or not the selected non de-duplication file exists in other file systems 413. If the non de-duplication file exists, the file server apparatus 4 cancels stubbing of the selected non de-duplication file. Specifically, the file server apparatus 4 moves entity data of the selected non de-duplication file from other file systems 413 to the migration source, deletes inode information and entity data of the selected non de-duplication file from other file systems 413, and sets the location of moved entity data to the metadata of the migration source.
At S3731, the file server apparatus 4 determines whether or not another non deduplication file to be selected exists. If a non de-duplication file exists (S3731: YES), the process returns to S3711, and if not (S3731: NO), the process proceeds to S3811 of
In this way, when the dependency of de-duplication files is low, the file server apparatus 4 migrates entity data to other file systems 413 by stubbing non deduplication files in a positive manner, thereby preventing load concentration to a specific LU 171 due to concentration of non de-duplication files to the specific LU 171 (file system 413).
At S3811 of
At S3813, the file server apparatus 4 implements the re-deduplication of deduplication files including the selected consolidation file and stores an identifier of the selected consolidation file. The stored identifier of the selected consolidation file is referenced at subsequent processing (such as S3911).
At S3831, the file server apparatus 4 determines whether or not another consolidation file to be selected exists. If such a consolidation file exists (S3831: YES), the process returns to S3811, and if not exist (S3831: NO), the process proceeds to S3911 of
In this way, when the dependency of de-duplication files is low, the file server apparatus 4 re-extracts common data from de-duplication files and re-organizes (re-deduplicate) the consolidation file and de-duplication files referring thereto, whereby improvements of the dependency and effects of load balancing by application of another load balancing method can be anticipated.
At S3911 of
Next, the file server apparatus 4 determines based on the acquired information whether or not the load balancing of the selected de-duplication file is necessary (S3913). This determination is made, for example, by checking whether or not access frequency of the selected de-duplication file exceeds a predetermined threshold. If determined that that the load balancing is necessary (S3913: YES), the process proceeds to S3914, if determined that the load balancing is not necessary (S3913: NO), the process proceeds to S3921.
At S3914, the file server apparatus 4 determines another file system 413 as a migration destination of the selected de-duplication file. The file server apparatus 4 selects the file system 413 as a migration destination of the selected de-duplication file (entity data) in such a manner that the load balancing functions efficiently (for example, in such a manner that the selected de-duplication file is allocated evenly to respective file systems 413.)
As a method for selecting a file system 413 as a migration destination of the selected de-duplication file, there is, for example, a method which assigns sequential identifiers to each of file systems which are selectable as a migration destination and selects a file system 413 assigned an identifier corresponding to a remainder obtained by dividing an inode number of the selected de-duplication file by a total number of file systems 413.
Next, the file server apparatus 4 generates an inode number of the selected deduplication file at the determined migration destination, and moves difference data of the selected de-duplication file to the migration destination (S3915). Further, the file server apparatus 4 sets the location (identifier of the file system 413 of the migration destination, inode number of the migration destination, and the like) of the difference data moved to the migration destination to the stub (metadata) of the migration source (S3916). Thereafter, the process proceeds to S3931.
On the other hand, at S3921, the file server apparatus 4 determines with reference to the stub of the migration source whether or not the selected de-duplication file exists in other file systems 413, and if the selected de-duplication file exists, the file server apparatus 4 moves difference data of the selected de-duplication file from the other file system 413 to the migration source, and deletes inode information and difference data of the selected de-duplication file from the other file system 413. Then, the file server apparatus 4 sets the location of the difference data moved to the migration source to metadata of the migration source (S3922).
At S3931, the file server apparatus 4 determines whether or not other consolidation files to be selected (consolidation files of which re-deduplication was determined not necessary at S3812 of
In this way, when the dependency of a de-duplication file is low, the file server apparatus 4 migrates difference data of the de-duplication file to other file systems 413 by stubbing the de-duplication file in a positive manner, thereby preventing load concentration to a specific volume due to concentration of de-duplication files thereto.
As described above, whenever a predetermined timing comes, the file server apparatus 4 determines a method of the load balancing based on the dependency of deduplication files, and in accordance with a determined method of the load balancing, distributes at least any one of consolidated data, difference data and non de-duplication file into a plurality of LUs 171. Therefore, data of files can be distributed into a plurality of LUs 171 in accordance with an appropriate method of the load balancing determined based on the dependency when a predetermined timing comes. Thus, when duplicated files are consolidated into a specific file for the purpose of data deduplication, a problem of load concentration to a specific file can be solved permanently, whereby effects of the load balancing can be obtained in a stable manner.
Note that the scheme of load balancing in the file server apparatus 4 described above may be implemented in conjunction with a scheme of distributing group of deduplication files among file server apparatuses 4 described above, or the scheme of the load balancing in the file server apparatus 4 may be implemented independently.
The scheme of load balancing in the file server apparatus 4 described above can further enhance effects of the load balancing by implementing in conjunction with a scheme of the load balancing among logical paths by local path management units 314, 414 described above.
When there is a difference in the performance or specification among LUs 171 to which file data is distributed, the information system 1 can be operated efficiently by appropriately distributing file data in further consideration of both performances and specifications.
The embodiments described above are provided to facilitate understanding of the present invention, but not to construe limitation of the present invention. The present invention may be modified and improved without departing from the spirit thereof and may include equivalents thereto.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2012/001014 | 2/16/2012 | WO | 00 | 3/6/2012 |
