JP2004334650A - Backup method, restoration method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a backup method for executing backup by designating a special file even at the time of using an OPC technique. <P>SOLUTION: Mounting processing is carried out for a volume(volume Vna) for backup in a recording device 20, and file information to be backed-up is extracted. Then, a correspondence table 10d in which the recording place of the data to be backed-up in the volume Vna for backup and the recording place of a recording medium 30 are made to correspond to each other is prepared based on the file information, and the data to be backed-up are reproduced from the volume Vna for backup to the recording medium 30 by referring to the correspondence table 10d. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for backing up data and a method for restoring data, and more particularly, to a method for a computer to back up data from a recording device such as a hard disk to a recording medium such as a tape medium for backup, and a method for recording data from a backed up recording medium to a recording device The restore method to restore data to
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in various tasks using a computer (computer), work has been performed using data recorded on a recording device such as a hard disk having a high access speed. However, since a hard disk having a drive mechanism has a higher failure rate than other electronic components, improvement of reliability has been an issue.
[0003]
In view of such a problem, in recent years, a device called a disk array (also called a RAID: Redundant Arrays of Independent Disks) has appeared, and a database server (hereinafter, referred to as a DB server) that needs to store a large amount of data has appeared. It is used for In a disk array, recording devices such as a plurality of hard disks are arranged in an array, and the same data is distributed and written to a plurality of drives to improve reliability.
[0004]
Now, even in such a disk array, data in the disk array is backed up to another recording medium such as a magnetic tape as necessary and restored when necessary, as in the related art ( For example, see Patent Document 1).
[0005]
In a DB (database) server or the like, since it is desirable that normal business can be operated 24 hours a day, 365 days, it is necessary to perform such backup processing and restore processing at high speed.
[0006]
As a technique for performing backup processing at high speed, there is a technique called OPC (One Point Copy).
The OPC technique is a function of copying a continuous block group on a logical unit (hereinafter referred to as a volume) in a disk array to an area on a different volume in the same disk array at a high speed.
[0007]
FIG. 7 is a diagram illustrating a conventional backup method using the OPC technology.
During the normal operation, the computer 70 performs the operation using the data of the volumes V1, V2,..., Vn of the disk array 80 using the normal operation processing unit 70a. At the time of backup, continuous blocks on the volumes V1, V2,..., Vn of the disk array 80 are copied to areas on different volumes V1a, V2a,. Data is backed up from the replicated volumes V1a, V2a,..., Vna in a tape device 90 using a magnetic tape or the like as a backup recording medium.
[0008]
By doing so, the time to stop the work is only the copy time (several seconds) by the OPC. Therefore, it appears to the user that the backup was performed at high speed.
[0009]
[Patent Document 1]
JP-A-10-01228 (paragraph numbers [0024] to [0033], FIG. 2)
[0010]
[Problems to be solved by the invention]
However, since the backup method based on the conventional OPC technique is a copy in units of volumes, it is not possible to select only a specific file (hereinafter, sometimes referred to as a directory) as a backup / restore target according to the type of data. . In particular, when restoring only a specific file, it is necessary to prepare an empty volume on the recording device side and restore the entire volume.
[0011]
Further, since the entire volume is backed up / restored irrespective of the used amount of the disk of the recording device, there is a problem that a certain time is always required for the backup / restore and that a tape of a certain capacity is consumed. there were.
[0012]
Further, since backup is performed for each file system layout in backup in units of volumes, it is necessary to operate the file system for restoration. That is, there is a problem that restoration cannot be performed in an environment where the corresponding file system is not operating.
[0013]
The present invention has been made in view of such a point, and an object of the present invention is to provide a backup method and a program which can perform a backup at a high speed by using the OPC technology and by specifying a specific file.
[0014]
Another object of the present invention is to provide a restore method and a program which can restore at high speed by specifying a specific file.
[0015]
[Means for Solving the Problems]
In the present invention, in order to solve the above problem, in a backup method in which a computer backs up data in a recording device to a recording medium for backup, as shown in FIG. .., Vn are mounted on backup volumes V1a, V2a, Vna prepared in the recording device 20 for copying and storing the data in the volumes V1, V2,..., Vn (step S1). The file information of the backup target file is extracted from the stored backup volume (step S2), and based on the file information, the data recording location of the backup target file in the backup volumes V1a, V2a, and Vna; The recording location on the recording medium (a tape device in the figure) 30 and A correspondence table 10d to be associated is created (step S3), and the data of the file to be backed up is copied from the backup volumes V1a, V2a, Vna to the recording medium 30 with reference to the correspondence table 10d (step S4). Is provided.
[0016]
According to the above-mentioned method, the file is mounted on a backup volume (for example, volume Vna) in the recording device 20, the file information to be backed up is extracted, and based on the file information, the backup volume Vna is used. A correspondence table 10d for associating the recording location of the data of the file to be backed up with the recording location on the recording medium 30 is created, and by referring to the correspondence table 10d, the data of the file to be backed up is recorded from the backup volume Vna to the recording medium 30. Therefore, the file is backed up for each file on the recording medium 30, and writing of unnecessary data is prevented.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic system configuration diagram of a system to which a backup method according to an embodiment of the present invention is applied.
[0018]
The system in FIG. 1 includes a computer 10, a disk array 20, and a tape device 30.
This system functions as, for example, a DB server system, and the computer 10 includes a normal operation processing unit 10 a that performs operations such as DB server processing and Web server processing (hereinafter, these are referred to as normal operations), It comprises a backup processing unit 10b for performing a backup process and a restore processing unit 10c for performing a restore process from the tape device 30.
[0019]
In the disk array 20, for example, a plurality of storage devices such as hard disks are arranged in an array. In such a disk array 20, a plurality of volumes V1, V2,..., Vn, V1a, V2a,.
[0020]
The tape device 30 stores data on a tape medium such as a magnetic tape, for example. It is a recording device that has a low access speed but stores a large amount of data. In the embodiment of the present invention, it is used for backing up and restoring data of the disk array 20.
[0021]
Hereinafter, the operation of the above system during the backup process will be described with reference to FIG.
When the normal operation is performed by the normal operation processing unit 10a, it is assumed that the computer 10 is performing operations using the data stored in the volumes V1, V2,..., Vn of the disk array 20.
[0022]
When the backup processing operation is started, the backup processing unit 10b prepares backup volumes V1a, V2a,..., Vna by the OPC technique in the same manner as the conventional one, and places the volumes V1, V2,. , Vn are duplicated. Next, in the embodiment of the present invention, the data block of the file to be backed up is mounted on the copy destination volume Vna of the volume having the data block (here, volume Vn). At this time, mounting on the volume Vna is performed as a file system different from the file system to which the backup target file belongs (step S1).
[0023]
When mounted on the volume Vna, the file information of the backup target file is extracted from the volume Vna.
The file information includes directory entry information and extent information.
[0024]
The directory entry information is information such as a file name, a size, an update date and time, an attribute, and a sector number of the first actual data in the volume, and can be extracted by a system call prepared by an OS (Operating System) as a standard.
[0025]
The extent information is information such as a logical position (block number) on the file, an address in the disk array 20, an area length of a plurality of data blocks constituting the file. The extraction of the extent information can be realized by using the technique disclosed in JP-A-2001-84168. According to this technique, extent information can be extracted by a method independent of a file system.
[0026]
The backup processing unit 10b recursively extracts directory entry information from the duplicated volume Vna, and when a file to be backed up is found, extracts extent information on the disk array 20 that constitutes the file (step S2).
[0027]
When the file information of all the files to be backed up is extracted, the file information is totaled, and a correspondence table 10d of the extent information on the disk array 20 and the extent information on the tape device 30 is generated.
[0028]
FIG. 2 is an example of the generated correspondence table.
As shown in the figure, for each file, the address of the data block constituting the file on the disk array 20 is associated with the address on the tape medium of the backup destination tape device 30 for storing the data block. (Step S3).
[0029]
Finally, the backup processing unit 10b refers to the correspondence table 10d generated in the process of step S3, and copies the data block of the file to be backed up to the tape device 30. For example, in FIG. 2, the address of the leading block on the disk array 20 of the continuous data block having the block number “blk = 0 to 3” of the file having the file name “file1” is “5977”. This is copied to the address “1000” on the tape medium of the tape device 30 and occupies the address “1003”. Consecutive data blocks with block numbers “4 to 7” have an address “10293” of the first block on the disk array 20, which is copied to an address “1004” on the tape medium of the tape device 30, and Occupies up to “1007”. Thus, duplication is performed. At the time of duplication, extent information (particularly, a file name, a block number, and an address in the tape device 30) of the correspondence table shown in FIG. 2 is also stored at the same time, and is used in a later-described restore process (step S4). ).
[0030]
As described above, since backup control can be performed for each file, only a specific file can be selected as a backup target according to the type of data.
[0031]
As a result, the backup time is shortened, and unnecessary data is prevented from being written, so that the capacity of the backup tape medium can be reduced.
Next, a case where data stored in the tape device 30 is restored to the disk array 20 will be described.
[0032]
FIG. 3 is a diagram illustrating a restore method according to the embodiment of this invention.
FIG. 3 has the same configuration as FIG. 1, and the same reference numerals are used. Note that, among the components appearing in FIG. 1, those not related to the description here are not shown.
[0033]
Hereinafter, the operation at the time of the restore processing will be described with reference to FIG.
When the restore operation is started, the restore processing unit 10c mounts on an arbitrary volume (for example, volume Vn) (Step S10). After that, file information (the above-described directory entry information and extent information) of the file to be restored is extracted from the tape device 30 (step S11). Next, a directory is created in the mounted volume Vn based on the extracted file information (step S12). The directory is created using a system call prepared by the OS as a standard. Finally, the data area is read from the tape device 30 based on the file information and written to the directory created in the process of step S12 (step S13). Note that writing to a directory can also be realized using a system call prepared as a standard by the OS.
[0034]
As described above, since restoration control can be performed for each file, only a specific file can be selected as a restoration target according to the type of data. This shortens the restore time.
[0035]
Next, an example of a hardware configuration of the computer 10 will be described.
FIG. 4 is an example of a hardware configuration of a computer according to the embodiment of this invention.
The computer 10 includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, a hard disk 14, a graphic processing unit 15, an input I / F (Interface) 16, a communication I / F 17, and the like. And these are interconnected via a bus 18.
[0036]
Here, the CPU 11 controls each unit according to a program stored in the hard disk 14.
The ROM 12 stores basic programs and data executed by the CPU 11.
[0037]
The RAM 13 temporarily stores programs that are being executed by the CPU 11 and data that is being computed (for example, the correspondence table 10d shown in FIG. 1).
The hard disk 14 stores an OS executed by the CPU 11, an HTTPd (HyperText Transfer Protocol daemon) as a server application, a program for performing the above-described backup processing and restore processing, and the like.
[0038]
The graphic processing unit 15 is connected to a display device 15a such as a display, and displays an image on the screen of the display device 15a in accordance with a drawing command from the CPU 11.
[0039]
A mouse 16 a and a keyboard 16 b are connected to the input I / F 16. For example, the input I / F 16 receives information input by an administrator of the computer 10 and transmits the information to the CPU 11 via the bus 18.
[0040]
The communication I / F 17 is connected to the disk array 20 via a network 40 that performs communication using a disk protocol called a storage area network (SAN).
[0041]
The processing of the embodiment of the present invention is realized by the hardware configuration as described above.
The processing functions of the normal operation processing unit 10a shown in FIGS. 1 and 3 are realized by executing a program such as HTTPd stored in the hard disk 14 under the control of the CPU 11. The backup processing unit 10b is realized by executing a program for performing a backup process under the control of the CPU 11. Similarly, the restore processing unit 10 c is realized by executing a program for performing a restore process under the control of the CPU 11.
[0042]
Hereinafter, the flow of the process of the computer 10 shown in FIG. 4 will be described using a flowchart, and the backup method and the restore method according to the embodiment of the present invention will be summarized.
[0043]
FIG. 5 is a flowchart illustrating a processing flow of the backup method according to the embodiment of this invention.
When a program for performing a backup process is extracted from the hard disk 14 under the control of the CPU 11 and executed, the CPU 11 starts controlling the backup process of the disk array 20 on the network 40 via the communication I / F 17.
[0044]
S20: The OPC-based replication CPU 11 prepares backup volumes V1a, V2a,..., Vna on the disk array 20 by the OPC technique as shown in FIG. A continuous block group on V2,..., Vn is copied.
[0045]
S21: Mount For example, when the administrator of the computer 10 inputs the information of the backup target file by operating the mouse 16a or the keyboard 16b, the information is converted into a data format readable by the computer 10 by the input I / F 16. Information on the backup target file is input to the CPU 11 via the bus 18. Based on this information, the CPU 11 mounts the copy destination volume Vna of the volume Vn where the data block of the backup target file on the disk array 20 exists. At this time, mounting on the volume Vna is performed as a file system different from the file system to which the backup target file belongs.
[0046]
S22: When mounted on the file information extraction volume Vna, the CPU 11 extracts the file information of the backup target file from the volume Vna.
[0047]
As described above, the file information includes the directory entry information and the extent information.
S23: When the correspondence table creation CPU 11 extracts the file information of all the files to be backed up, the CPU 11 totals them, and as shown in FIG. 2, the recording location of the data of the file to be backed up on the disk array 20 (see FIG. A correspondence table 10d in which addresses (addresses) are associated with recording locations on the tape device 30 is generated and temporarily stored in, for example, the RAM 13.
[0048]
S24: The data block of the file to be backed up is copied to the tape device 30 under the control of the CPU 11 with reference to the correspondence table 10d generated in the process of the data copying step S23. At the time of copying, the extent information (particularly, file name, block number, and address in the tape device 30) of the correspondence table shown in FIG. 2 is also stored on the tape medium of the tape device 30 at the same time.
[0049]
FIG. 6 is a flowchart illustrating the flow of processing of the restore method according to the embodiment of this invention.
When a program for performing a restore process is retrieved from the hard disk 14 under the control of the CPU 11 and executed, the CPU 11 starts controlling the restore process to the disk array 20 on the network 40 via the communication I / F 17. .
[0050]
S30: The mount CPU 11 mounts an arbitrary volume Vn on the disk array 20 selected by the input of the administrator.
[0051]
S31: Extract File Information Next, the CPU 11 extracts, from the tape device 30, file information (the above-described directory entry information and extent information) of the file to be restored.
[0052]
S32: The directory creation CPU 11 creates a directory in the mounted volume Vn based on the extracted file information.
[0053]
S33: Data Replication Finally, the CPU 11 reads the data area from the tape device 30 based on the file information and writes the data area into the directory created in the processing of step S12.
[0054]
According to the backup method and the restore method as described above, at the time of backup, data is stored in a format that does not depend on the file system layout of the copy source, so that restoration can be performed using an arbitrary file system. Therefore, it is not necessary to operate an old file system to restore old data. Further, by selecting a desired file system at the time of restoration, conversion of the file system can be realized.
[0055]
In the above description, a case where a disk array is used as a recording device and a tape medium is used as a backup recording medium has been described as an example, but the present invention is not limited to this. The recording device may be any device that can be accessed as a file system. For example, a large-capacity nonvolatile memory may be used. Further, as a recording medium for backup, an optical disk such as a DVD (Digital Versatile Disc), a CD-ROM (Compact Disc Read Only Memory), a CD-R (Recordable) / RW (ReWritable), or a hard disk may be used. .
[0056]
As described above, the above processing functions can be realized by a computer (computer). In this case, a program describing the processing contents of the functions that the computer 10 should have is provided. By executing the program on a computer, the above processing functions are realized on the computer. The program describing the processing content can be recorded on a computer-readable recording medium. Computer-readable recording media include magnetic recording devices, optical disks, magneto-optical recording media, and semiconductor memories. The magnetic recording device includes a hard disk, a flexible disk (FD), a magnetic tape, and the like. The optical disk includes a DVD, a DVD-RAM (Random Access Memory), a CD-ROM, a CD-R / RW, and the like. Magneto-optical recording media include MO (Magneto-Optical disc).
[0057]
When distributing the program, portable recording media such as DVDs and CD-ROMs on which the program is recorded are sold. Alternatively, the program may be stored in a storage device of a server computer, and the program may be transferred from the server computer to another computer via a network.
[0058]
The computer that executes the program stores, for example, the program recorded on the portable recording medium or the program transferred from the server computer in its own storage device. Then, the computer reads the program from its own storage device and executes processing according to the program. The computer can also read the program directly from the portable recording medium and execute processing according to the program. Further, the computer may execute the processing according to the received program each time the program is transferred from the server computer.
[0059]
(Supplementary Note 1) In a backup method in which a computer backs up data in a recording device to a backup recording medium,
For duplicating and storing data in the volume of the recording device, mounted on a backup volume prepared in the recording device,
Extracting file information of a backup target file from the backup volume in which the copied data is stored,
Based on the file information, create a correspondence table that associates the recording location of the data of the backup target file in the backup volume with the recording location in the recording medium,
Referring to the correspondence table, copying the data of the backup target file from the backup volume to the recording medium,
A backup method characterized in that:
[0060]
(Supplementary note 2) The backup method according to supplementary note 1, wherein the file information is directory entry information and extent information of the backup target file.
[0061]
(Supplementary Note 3) In a restore method in which a computer restores data from a backup recording medium to a recording device,
From the recording medium, mounted on a volume in the recording device for restoring the data to be restored,
Extracting file information of the file to be restored from the recording medium,
Create a directory on the volume based on the file information,
Writing the data of the file to be restored to the directory,
Restoration method characterized by the above-mentioned.
[0062]
(Supplementary Note 4) In a program that causes a computer to execute a process of backing up data in a recording device to a backup recording medium,
Computer
Mounting means for mounting on a backup volume prepared in the recording device, for copying and storing data in the volume of the recording device,
File information extraction means for extracting file information of a backup target file from the backup volume in which the copied data is stored,
Correspondence table creation means for creating a correspondence table for associating a data recording location of the backup target file in the backup volume with a recording location in the recording medium based on the file information,
A data copying unit that copies the data of the backup target file from the backup volume to the recording medium with reference to the correspondence table;
A program to function as
[0063]
(Supplementary Note 5) In a program that causes a computer to perform a process of restoring data from a backup recording medium to a recording device,
Mounting means for mounting from the recording medium to a volume in the recording device for restoring the data to be restored,
File information extracting means for extracting file information of the file to be restored from the recording medium,
Directory creation means for creating a directory in the volume based on the file information;
Data writing means for writing data of the file to be restored to the directory,
A program to function as
[0064]
(Supplementary Note 6) In a computer-readable recording medium storing a program for causing a computer to perform a process of backing up data in a recording device to a recording medium for backup,
Computer
Mounting means for mounting on a backup volume prepared in the recording device, for copying and storing data in the volume of the recording device,
File information extraction means for extracting file information of a backup target file from the backup volume in which the copied data is stored,
Correspondence table creation means for creating a correspondence table for associating a data recording location of the backup target file in the backup volume with a recording location in the recording medium based on the file information,
A data copying unit that copies the data of the backup target file from the backup volume to the recording medium with reference to the correspondence table;
A computer-readable recording medium that records a program that functions as a computer.
[0065]
(Supplementary Note 7) In a computer-readable recording medium storing a program that causes a computer to perform a process of restoring data from a backup recording medium to a recording device,
Mounting means for mounting from the recording medium to a volume in the recording device for restoring the data to be restored,
File information extracting means for extracting file information of the file to be restored from the recording medium,
Directory creation means for creating a directory in the volume based on the file information;
Data writing means for writing data of the file to be restored to the directory,
A computer-readable recording medium that records a program that functions as a computer.
[0066]
【The invention's effect】
As described above, in the present invention, a technique is used in which data in a volume of a recording device is copied to a backup volume prepared in the same recording device and then backed up to a backup recording medium. Also, backup control can be performed for each file. As a result, the backup time is shortened, and the capacity of the backup recording medium can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic system configuration diagram of a system to which a backup method according to an embodiment of the present invention is applied.
FIG. 2 is an example of a generated correspondence table.
FIG. 3 is a diagram illustrating a restore method according to the embodiment of this invention.
FIG. 4 is a hardware configuration example of a computer according to the embodiment of this invention.
FIG. 5 is a flowchart illustrating a processing flow of a backup method according to the embodiment of this invention.
FIG. 6 is a flowchart illustrating a processing flow of a restoration method according to the embodiment of this invention.
FIG. 7 is a diagram illustrating a conventional backup method using the OPC technology.
[Explanation of symbols]
Reference Signs List 10 Computer 10a Normal operation processing unit 10b Backup processing unit 10c Restore processing unit 10d Correspondence table 20 Disk array 30 Tape device

Claims (5)

In a backup method in which a computer backs up data in a recording device to a recording medium for backup,
For duplicating and storing data in the volume of the recording device, mounted on a backup volume prepared in the recording device,
Extracting file information of a backup target file from the backup volume in which the copied data is stored,
Based on the file information, create a correspondence table that associates the recording location of the data of the backup target file in the backup volume with the recording location in the recording medium,
Referring to the correspondence table, copying the data of the backup target file from the backup volume to the recording medium,
A backup method characterized in that: 2. The backup method according to claim 1, wherein the file information is directory entry information and extent information of the backup target file. In a restore method in which a computer restores data from a backup recording medium to a recording device,
From the recording medium, mounted on a volume in the recording device for restoring the data to be restored,
Extracting file information of the file to be restored from the recording medium,
Create a directory on the volume based on the file information,
Writing the data of the file to be restored to the directory,
Restoration method characterized by the above-mentioned. In a program that causes a computer to perform a process of backing up data in a recording device to a recording medium for backup,
Computer
Mounting means for mounting on a backup volume prepared in the recording device, for copying and storing data in the volume of the recording device,
File information extraction means for extracting file information of a backup target file from the backup volume in which the copied data is stored,
Correspondence table creation means for creating a correspondence table for associating a data recording location of the backup target file in the backup volume with a recording location in the recording medium based on the file information,
A data copying unit that copies the data of the backup target file from the backup volume to the recording medium with reference to the correspondence table;
A program to function as In a program that causes a computer to perform a process of restoring data from a recording medium for backup to a recording device,
Mounting means for mounting from the recording medium to a volume in the recording device for restoring the data to be restored,
File information extracting means for extracting file information of the file to be restored from the recording medium,
Directory creation means for creating a directory in the volume based on the file information;
Data writing means for writing data of the file to be restored to the directory,
A program to function as

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