JP3043662B2 - Data backup method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data backup system, and more particularly to a data backup system capable of performing an update process even during a data backup.

[0002]

2. Description of the Related Art Recent data processing systems include noise and noise.
There is a need to recover data from overall events such as data processing system power failures, as well as loss of stored data accuracy due to bursts, software bugs, media defects, and write path errors. The most common approach to ensuring continuous availability of data in a data processing system is to generate at least one copy of a selected set of data in the data processing system and store these copies in a non-volatile storage medium. To be stored. This backup process is usually performed in an external storage medium system.

As one of such data backup methods, for example, as described in Japanese Patent Application Laid-Open No. Hei 6-83677, "Method and System for Incremental Time Zero Backup Copy of Data" In order to retain the data at the start of the backup until the end of the backup, the following method has been adopted.

That is, the time zero backup
In the copy system, a determination is first made whether the update to the tracked patrol storage for backup attempted by the application is for a volume that is not in the current copy session. If this volume is not in the current copy session, the update ends normally.

Alternatively, if the update is for a volume that is part of a copy session, the primary session bit map is examined to see if the track is protected. The update is successful if the corresponding bit in the bit map is off, indicating that the track is not currently in a copy session.

[0006] However, if the recording track of the tracked cyclic storage is protected (the corresponding bit in the bitmap is on), the recording track in question is part of the copy session and is still in the copy session. Not read by the resource manager that notifies start / end. In such a case, the storage control mechanism of the cache memory temporarily buffers the update and writes a copy of the affected track from the tracked traversal storage to memory in the storage control mechanism. Thereafter, updates can be made to the tracking patrol storage device.

When a backup copy is performed, the data of a track that has not been updated is directly transferred from the tracking and revolving storage device, and the data of the updated track is data that has been written to the memory in the storage control mechanism. .

[0008]

However, before updating the area in the copy session of the tracking and traveling storage device, it is necessary to perform the updating process after transferring the target area to the memory in the storage management mechanism. Therefore, when an application updates an area during a copy session of an external storage device, there is a problem in that performance is deteriorated which requires an increase in backup time.

Accordingly, an object of the present invention is to reduce the update processing time of data frozen for backup processing.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made in consideration of the above-described problems, and provides a data backup method for a system in which an application controls a file device via a device driver. An alternative file device to be used at the time of backup for backup, and the operation file device /
And access switching means to alternate file system, and means for controlling the back <br/> up, the access switching means, the substitute file system to write to the management file unit generated during the backup execution If the operation file device is read to the area written to the alternative file device, has a function of performing access switching to read from the alternative file device, the means for controlling the backup, Previous
After completion of the serial backup, and having a function of transferring the data written to the alternate file system in the corresponding area of the running file system.

[0011] The present invention also provides an application program.
In a data backup method of a system in which a file device is controlled via a device driver by a RAM,
An operation file device for writing and reading normal data,
A backup file device used for backup for backup, and an access switching unit for switching access to the operation file device / alternate file device, wherein the access switching unit includes the operation file device generated during the backup execution Is written to the alternative file device, and if the operation file device is read from the area written to the alternative file device, the operation file is read from the alternative file device. In front of the device
It has the function of performing serial backup, and characterized by having a function of transferring the data written to the Backing <br/>-up to the end after the substitute file system in the corresponding area of the running file system.

In the data backup method, the access switching means comprises an address conversion module, and the access switching converts the address of the active file device and the address of the substitute file device according to the contents of an address conversion table. It is characterized by doing.

According to the present invention, in a data backup method for controlling a file device via a device driver by an application program, the device driver receives an input / output request from the application program, and the device driver transmits the input / output request via an address conversion module. An input / output bus for sending the input / output request, a backup module connected to the input / output bus for receiving a backup request from a backup management application, and an address converter connected to the backup module and the address conversion module. A table, an operating device connected to the input / output bus for writing / reading normal data in accordance with the application program, and a data buffer connected to the input / output bus. Comprising a backup device for up, and alternative devices to be replaced if there is a write-read request to the management device in the connected backup execution to said output bus, said address translation
The table shows the operating device during the backup.
The operation written when a write / read request to the
For address translation between the
Bull.

[0014] Also, in the above-mentioned data backup system, writes to the operational file system that occurs during the backup execution to the alternative file system, the read of the operation file device area written to the alternate file system If it has been performed on the substitute file device, it is read from the substitute file device, and the substitute file device has a function of backing up the operation file device.

More specifically, referring to FIG. 1, the data backup method of the present invention differs from the operation device (7 in FIG. 1) for storing normal data, and is replaced with an alternative device (FIG. 1) used at the time of backup. 1-9), access switching to the operation / alternate file device (3 in FIG. 1), a function of controlling backup (5 in FIG. 1), and an address conversion table (5) used for access switching and backup control. 1) of FIG.

The writing to the operation file device, which occurs during the execution of the backup, is performed to the alternative file device, and the data of the operation device is retained at the time when the backup was started. If the reading during backup is for an area written to the alternative file device, reading from the alternative file device makes the general application look the same as writing to the operating device. At the time of writing, there is no change in the processing time because the place that should originally be written to the operation device is merely writing to the substitute device.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a system configuration example showing an example of the first embodiment of the present invention. In the embodiment shown in FIG. 1, an input / output request from a general application program 1 is issued to a device driver 2, and the device driver 2 is connected to an input / output bus 10 through an address conversion module 3. A backup request from the backup management application 4 is issued to the backup module 5, and the backup module 5
Connected to 0. The backup module 5 is connected to the address conversion module 3, the address conversion module 3 is connected to the address conversion table 6, and the backup module 5 is also connected to the address conversion table 6.
The address translation table 6 stores a substitution source and a substitution destination as a pair. The substitution source includes the ID of the operation device 7 of the operation file device, the address and the count, and the corresponding substitution destination includes: The address of the substitute file device on the substitute device 9 is recorded. The operation device 7, the backup device 8, and the substitute device 9 are connected to the input / output bus 10 as storage media.

Next, the operation of the embodiment shown in FIG. 1 will be described in detail with reference to FIGS.

Normally, an input / output request from the general application 1 is issued to the device driver 2, and the input / output request is subsequently connected to the input / output bus 10 from the device driver 2 via the address conversion module 3. It is issued to the operating device 7 that has been set. Thus,
In a normal operation, a general application program stores data in the operation device 7 or reads out data stored in the operation device 7 via the input / output bus 10 and executes a predetermined processing program. ing.

On the other hand, a backup request from the backup management application 4 is issued to the backup module 5.

FIG. 2 shows the backup module 5 of the present invention.
FIG. When the backup process is started, the address translation table 6 is initialized in an operation step S1. Thereafter, in the operation step S2, a notice to start the backup processing is sent to the address conversion module 3. Then, as will be described later, the address conversion module 3 starts converting the address of access to the operation device 7 to the address of the substitute device 9 as necessary. The backup module 5 transfers the data of the operation device 7 to the backup device 8 in the operation step S3.

When the transfer of all data is completed, in operation step S4, it is checked whether or not address conversion data is written in the address conversion table 6 by the address conversion module 3 during data backup. If the check result data exists, in operation step S5,
The address conversion module 3 is notified that the recovery of the first alternative data in the address conversion table 6 is to be started. Then, the update data written in the substitute device 9 is restored to the operation device 7 in the operation step S6, and the data of the restored address translation table 6 is cleared in the operation step S7. After that, in the operation step S8, the completion of the recovery work on the data is notified to the address conversion module 3. Then, the operation step S
4, the data of the address conversion table 6 is checked again. When the restoration of all the data subjected to the substitution processing is completed, the end of the backup processing is notified to the address conversion module 3 in operation step S9.

FIG. 3 shows the address translation module 3 of the present invention.
FIG. When the input / output processing is started, it is determined in operation step S11 whether the operation device 7 is backing up. If you are backing up,
The backup module 5 notifies the user that the backup is being performed. If the backup is not being performed, the address conversion module 3 issues the input / output request of the general application 1 to the operation device 7 without performing the address conversion in the operation step S12. If the backup is being performed, the process proceeds to operation step S13,
Since the general application 1 is running, it is determined whether or not the area of the input / output request of the general application 1 during the operation exists in the address conversion table 6. If the area of the input / output request does not exist in the address translation table 6, it is checked in step S14 whether the input / output request is a Read command.
Issue an ead instruction. If the result of the check in operation step S14 is that the instruction is a Write instruction, operation step S16
Then, the address of the alternative device 9 is registered in the address conversion table 6, and a write instruction to the alternative device 9 is issued in operation S17.

If the address conversion table 6 already exists in the operation step S13, it is checked in step S18 whether the request is a write request. If the request is a read request, the address conversion table 6 is checked in operation step S19. 6, the address is converted from the data of step 6, and the operation step S
At 20, a Read command / Write command is issued to the substitute device 9. If the check in operation step S18 indicates a write request, it is checked in operation step S21 whether the target area is being restored. During the recovery, information indicating that the recovery is being performed is notified from the backup module 5. If the recovery is not being performed, the processing of the above-described operation step S19 is performed. If the recovery is being performed, the operation waits until the recovery work for the area is completed in operation step S22. When the recovery work is completed, the operation device 7 is operated in operation step S23.
Issues a write request to

In the above-described embodiment, an example has been described in which the update data being backed up is stored in the substitute device. However, this may be stored in the main memory or in the cache memory. Needless to say.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIG. In a system in which the general application program 11 controls the file device 13 via the device driver 12, the alternative file device 16 used for backup separately from the normal operation file device 15 and the access switching to the operation / alternate file device and backup. File device 1 that has the function of controlling
5 is written to the alternative file device 16, and if the read is to the area written to the alternative file device 16, the data is read from the alternative file device 16 and the backup of the operation file device 15 is performed. After the backup is completed, the data written to the substitute file device 16 is transferred to the corresponding area of the operation file device 15.

An input / output request from the general application 11 is issued to the device driver 12, and is issued from the device driver 12 to the operation device 15 through the address management module 13. When the backup of the operation device 15 needs to be performed, the backup management application 14 sets a flag indicating that the backup is being performed, and instructs the address management module 13 to perform an alternative access process. In response to this instruction, the address management module 13 writes the address of the write request to the operation device 15 together with the device name of the operation device and the count number indicating the write capacity to the substitution source 21 of the address conversion table 20, and The device name and its address of the device 22 are determined, and writing is performed on the substitute device 16. On the other hand, when a read request is received, the address conversion table 20 is searched to determine whether or not the area has been written to the alternative device 16.
Read data from

After the above processing, the backup management application 14 instructs the disk address management module 13 to back up the data of the operation device 15 to the backup device 17. In response to this instruction, the address management module 13 transfers the data of the operation device 15 to the backup device 17 while performing the above-described alternative processing. When the backup is completed, the backup management application 14 instructs the address management module 13 to write the data of the alternative device 16 to the original area of the operation device 15. The address management module 13 returns the data of the substitute device 16 to the operation device 15 with reference to the internal address conversion table 20.

As described above, the backup data retains the contents of the data at the time of starting the backup, and the system can be operated without stopping the operation of the application program during the execution of the backup while ensuring data consistency. .

In the above-described embodiment, the writing / reading to / from the operation device 15 is replaced with the alternative device 16 from the time when the backup execution start is instructed.
If the backup is performed periodically, the backup device may be replaced with the replacement device 16 when the regular time comes.

In the above embodiment, the alternative device 1
6 is used, a device name of the substitution destination 22 is recorded in the address conversion table 20. However, when one substitution device 16 is used, this device name column is not required. It is.

[0033]

According to the present invention, instead of once reading out and backing up data to be backed up and writing the updated data there, it is only necessary to read out the data written directly to the alternative device and write it to the operating device. Since there is no need to read data from the backup device, the time required to update data frozen for backup processing can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the backup module shown in FIG. 1;

FIG. 3 is a flowchart for explaining an operation of the address conversion module shown in FIG. 2;

FIG. 4 is a system configuration diagram showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 General application 2 Device driver 3 Address conversion module 4 Backup management application 5 Backup module 6 Address conversion table 7 Operation device 8 Backup device 9 Alternative device 10 I / O bus S1-S9, S11-S23 Operation steps

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-232449 (JP, A) JP-A-2-133845 (JP, A) JP-A-4-65733 (JP, A) JP-A-4-234 235639 (JP, A) JP-A-4-235645 (JP, A) JP-A-6-83677 (JP, A) JP-A-6-83679 (JP, A) JP-A-6-83686 (JP, A) JP-A-6-83687 (JP, A) JP-A-7-281933 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G06F 12/00

Claims (5)

(57) [Claims] In a data backup method of a system in which an application controls a file device via a device driver, an operation file device for storing normal data, an alternative file device used at the time of backup, and the operation file device / alternative file and access switching means to the device, before
And means for controlling the serial backup, the access switching means performs writing into the running file system that occur while the backup execution to the substitute file device, for reading the operation file device the substitute file system has a function of performing read access switch from the alternate file system if the the in made to written area, means for controlling the backup, after completion of the backup, the data written to the alternate file system A data backup method having a function of transferring data to a corresponding area of the operation file device. 2. A data backup system for controlling a file device via a device driver by an application program, comprising : an operating file device for writing / reading normal data;
Disconnect the alternate file device used for backup and access to the operation file device / alternate file device.
And an access switching means replacing said access switching means performs writing to the running file system that occur while the backup execution to the alternate file system, writing reading of the operation file device to the alternate file system If performed on the area, read from the alternative file device,
Has a function of the alternate file system performs the bus <br/> Kkuappu of the operation file device, and transfers the data written to the backup to the end after the substitute file system in the corresponding area of the running file system A data backup method characterized by having a function. 3. The data backup method according to claim 1, wherein the access switching unit writes and reads data from / to the operation file device generated during the execution of the backup, and performs an address conversion relationship with the substitute file device. A data backup method for converting the address of the operation file device and the address of the substitute file device in accordance with the contents of the address conversion table. 4. An application program for decoding data.
Device that controls a file device through a device driver
Data input / output request from the application program
The device driver and the device driver
Sends the input / output request via the address conversion module.
Output I / O bus and backup management application
To the I / O bus that receives the backup request from the
Connected backup module and the backup module
Connected to the address conversion module and the address conversion module.
Address conversion table connected to the input / output bus.
Normal data according to the application program
An operation device for writing and reading
Backup data connected to the bus for data backup
And connected to the I / O bus to execute backup
Request for writing / reading to the operating device during
The address conversion table, wherein the address translation table is a table for address translation of the operation device and the substitution device written at the time of a write / read request to the operation device during the backup. Data backup method characterized by the following. 5. The data backup method according to claim 4 , wherein writing to the operation file device, which occurs during the execution of the backup, is performed to the alternative file device, and reading of the operation file device is performed to the alternative file device. A data backup method for reading from the replacement file device if the writing has been performed on the written area, and the replacement file device having a function of backing up the operation file device.