JP2000305719A - Method for backing-up data in information processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To back-up data to be used by an open system side in a back-up device connected with a main frame in a computer system in which the main frame and the open system coexist. SOLUTION: In this back-up method, the data of a volume for back-up provided at an outside storage device 4 or a volume 52 for an open system through a communication line 34 are transferred from an open frame 2 to a main frame 1 in response to a request for the reading of the data of the volume 52 for the open system from the main frame 1. The main frame 1 converts fixed length recording format data transferred by a recording device control processor 14 into a variable length recording format data, and stores the converted variable length recording format data in a back-up device 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for obtaining a backup of data stored in a storage device and a method for restoring the same in a computer system.

[0002]

2. Description of the Related Art As a storage device used in a computer system, a disk array has been generally used from the viewpoint of high performance and high reliability. In a so-called open system such as a workstation or a personal computer (PC), a fixed-length recording format is used as a data recording format in an external storage device such as a disk device. Therefore, an interface between the open system and the disk array controller generally adopts a fixed-length access interface. The fixed-length access interface is also used for individual disk devices inside the disk array.

On the other hand, in a general-purpose large-sized computer (hereinafter referred to as a mainframe), a variable-length recording format is applied to data recording on a magnetic disk device. For this reason,
For access to the magnetic disk device, a variable length access interface such as CKD (Count Key Data) that enables data access in a variable length recording format is used. Conventionally, data in a variable length recording format has been physically recorded on a disk device having a variable length access interface. However, in recent years, a disk array including a relatively inexpensive disk device used in a PC or a workstation has been widely used as a storage device for recording data in a variable-length recording format.

In the case of a mainframe disk array,
"Mainframe '98", Nikkei BP, pp. 126-
As seen at 130, each disk drive has F
It is common to use a disk device on which data is recorded in a fixed-length recording format called a BA (Fixed Block Architecture) format. The disk array controller has a function of converting between a fixed-length recording format and a variable-length recording format using a cache memory, and the mainframe and the disk controller are connected by a variable-length access interface. A read / write request from the mainframe is composed of a plurality of input / output commands called CCW (Channel Command Word). These multiple CCWs are called a CCW chain. CC
The W chain is created by the mainframe operating system in accordance with a request from an application.

Usually, a magnetic disk device is provided outside a main frame as a disk subsystem composed of a disk control device and a disk device. When reading / writing data to / from the disk device, the mainframe sends a command according to a variable-length recording format to the disk subsystem. The disk control device provided in the disk subsystem receives a command instructed from the mainframe, and converts data from a variable-length recording format to a fixed-length recording format in order to access the disk device. Such conversion from the variable-length format to the fixed-length format is disclosed, for example, in Japanese Patent Laid-Open No. 6-150557.

[0006] In recent years, computer centers are often composed of a mixture of a mainframe and an open system. In such a configuration, in order to facilitate the management of the disk array, it is required that the data accessed by each of the mainframe and the open system be stored in common and the disk array be unified. Techniques that meet such demands include, for example, “Mainframe '9
8 ”, page 145 or page 151 of Nikkei BP,
There has been disclosed a technique for accessing mainframe data stored in a disk array having both a variable-length access interface and a fixed-length access interface from an open system. Here, the data of the mainframe is converted into a variable-length / fixed-length recording format in a disk array, and stored in a fixed-length recording format disk device. The mainframe data stored in the disk device is taken out to the open system server as it is stored in the disk device through an interface of a fixed length recording format.

Further, by using the backup / restore option function of the mainframe, a volume for an open system on the disk array can be read from the mainframe as a volume image and backed up. Also, the backed up data can be restored from the mainframe side to the open system volume. No special software needs to be installed on the mainframe and open system side to use this function. The disk array controller converts the data of the fixed-length recording format of the volume for the open system into data of the variable-length recording format so that the data can be accessed from the mainframe. As a backup destination, an existing tape library device, MT (Magne
tips), a disc, and the like. For a volume for an open system in the disk array, a volume serial number and a volume list are created at the time of volume initialization.
Since the volume serial number and the volume list written to the volume by the initialization are written in an area different from the area where the data of the open system is written, the data of the open system is not destroyed. Data stored in another disk device connected to the server to which the disk array is connected, and
Data stored in a disk device connected to a server / client on another network (data stored outside the disk array) is stored in the disk array using a backup program or system command on the open system side. Is backed up to the backup / restore volume in which the list of volumes and the volume serial number initialized by the above are created. The data backed up to the backup / restore volume is further backed up to a tape library device or the like using the mainframe-side backup function as described above.

On the other hand, as an external storage device interface of a general-purpose information processing device, a device having a SCSI interface which is a fixed-length access interface has appeared. For example, "Mainframe '98", Nikkei BP, pp. In the built-in disk device described in 53-54, a disk device of a fixed length recording format is built in the housing of the information processing device. A command group (CCW) for reading / writing data in the variable-length recording format generated by the operating system is interpreted by a processor called SAP and converted into a command group (SCSI command) for reading / writing data in the fixed-length recording format. The data is converted and the input / output processing to / from the internal disk is executed. The built-in disk device stores data in a variable-length recording format embedded in a fixed-length recording format. Such data format conversion is performed by the SAP.

[0009]

According to the above-mentioned prior art, when the open system backs up data in an external storage device shared by the open system and the mainframe to the backup storage on the mainframe side, the mainframe is It is necessary to copy data once into the backup volume of the shared external storage device. Therefore, it is necessary to create a backup volume every time a backup is performed. That is, two backup operations are required for one backup operation. For this reason, processing for securing the storage capacity and performing the backup operation occurs.

An object of the present invention is to provide a backup method for reducing the area of a backup volume used for a backup operation and reducing the overhead of the backup operation.

[0011]

According to a first aspect of the present invention, a computer is connected to a first computer, a second computer, and the second computer. A first storage device storing data in a fixed-length recording format used by the second computer, and a backup device connected to the first computer and storing data in a variable-length recording format. In order to back up the data stored in the first storage device to the backup device, a backup method including the following steps is provided. The first computer requests the second computer to read the data in the fixed-length recording format. In response to the request, the second computer reads the data in the fixed-length recording format from the first storage device and transfers the data to the first computer. The first computer converts the transferred fixed-length recording format data into variable-length recording format data, and stores the converted variable-length recording format data in a backup device.

According to a second aspect of the present invention, a fixed length record connected to a first computer, a second computer, both a first computer and a second computer, and used by the second computer. For backing up data stored in a storage device to a backup device in a computer system having a storage device storing data in a format and a backup device connected to the first computer and storing data in a variable length recording format A backup method including the following steps is provided. Volume information for accessing the fixed-length recording format data from the first computer is stored in an area that is distinct from the area where the fixed-length recording format data is stored. The first computer reads the data of the fixed-length recording format from the storage device based on information included in the volume information. In the first computer, data in the fixed-length recording format is converted into data in the variable-length recording format. The first computer stores the data converted into the variable-length recording format in a backup device.

[0013]

FIG. 1 is a schematic block diagram of a computer system according to an embodiment of the present invention. The mainframe 1 has a central processing unit (CP)
U) 12, a main storage device 11, communication devices (I / O channels) 13, 15, 16 for controlling the exchange of information and data with other information processing devices, and one or more storage device control processors 14. Having. The I / O channel 13 has a variable length access interface and is connected to the backup device 3 via the communication line 30. I / O channel 1
5 has a fixed-length access interface, and has a communication line 3
1 is connected to the external storage device 4. As the fixed-length access interface between the I / O channel 15 and the external storage device 4, for example, SCSI (Small Computer)
System Interface) or SCSI on Fiber Channel based on optical cable
An interface equipped with a protocol can be used. In addition to an area for storing data and programs used by the CPU 12, a cache memory 111 used when data is input / output to / from the external storage device 4 is allocated to the main storage device 11. Cache memory 11
1 serves as a disk cache. The storage device control processor 14 has a data recording format conversion mechanism 141 which is a conversion function between a variable length recording format and a fixed length recording format. In the present embodiment, the data recording format conversion mechanism 14
1 is realized as a program executed by the storage device control processor 14. Storage device control processor 1
4 also controls data transfer between the external storage device 4 and the main storage device 11. The cache memory 111 holds data read from the external storage device 4 and data written by the CPU 12 to the external storage device 4. Data is,
The data is stored in the cache memory 111 in the same fixed-length recording format as the external storage device 4.

The open system 2 is a server device, and includes a central processing unit (CPU) 22, a main storage device 21, and a communication device (I / O) for controlling the exchange of information and data with other information processing devices. Channel) 23, 24. The I / O channel 23 and the I / O channel 13 are variable-length access interfaces. Main frame 1
And the open system 2 communicate with the I / O channel 16 and the I / O
The channel 24 is connected via a communication line 34.
The I / O channel 23 has a fixed-length access interface, and is connected to the external storage device 4 via a communication line 32. The I / O channel 23 is also connected to the external storage device 5 via a communication line 33.

The external storage device 4 uses the mainframe 1 as a server. The external storage device 4 stores data in a fixed-length recording format and has a fixed-length access interface. The external storage device 4 can be a single disk device or a RAID (Redundan) having a fixed-length access interface.
t Array of Inexpensive Disks). The external storage device 4 has a mainframe volume 42 and an open system volume 43. The mainframe volume 42 is a volume for storing data of the mainframe 1 and is accessible only from the mainframe 1. The open system volume 43 is a volume for storing data of the open system 2. In the open system volume 43, volume information and a volume serial number of the open system volume 43 are created by the volume information creation / data set allocation module 1121 of the mainframe system 1 and an initialization process.

As the backup device 3, for example, an MT library device using a magnetic tape (MT) as a storage medium is used. As the backup device 3, a disk device can be used instead of the MT library device.

FIG. 2 shows a volume 4 for an open system.
FIG. 3 is a schematic diagram showing a logical configuration of No. 3; In the open system volume 43, volume information 431 and a volume serial number 433 are stored. Volume information 4
Reference numeral 31 has information for identifying the start and end positions of the user data 432 in the volume 43. The volume serial number 432 is an identifier given to identify the volume 43 from another volume. The volume information 431 and the volume serial number 433 are
The data is written in an area different from the area in which the user data 432 for the open system is written. Therefore,
Thus, the user data 432 for the open system is not destroyed. By creating the volume information 431 and the volume serial number 433, the open system volume 43 can also be accessed from the mainframe 1. However, only the backup / restore program 112 can access the open system volume 43 from the mainframe 1 side. The volume information 431 is stored in a variable length recording format, and the user data for the open system is stored in a fixed length recording format. The volume information 431 and the volume serial number 433 can be stored in another volume independent of the open system volume 43 or in the cache memory 111 of the mainframe 1 in addition to the above.

Volume information and a volume serial number necessary for backing up the data of the open system volume 52 of the external storage device 5 are created in the mainframe 1 or the external storage device 4. The operating system 113 makes it appear that the volume exists in the mainframe 1 or the external storage device 4, and the volume serial number identification means 142 of the storage device control processor 14 determines where the actual volume is. The storage device control processor 14 selects a process according to the storage location identified by the volume serial number. When the volume is in the external storage device 4, backup processing of the corresponding volume is directly performed. When the volume is in the external storage device 5, data to be backed up through the open system 2 to which the external storage device 5 is connected is stored. get.

FIG. 3 is a schematic diagram showing a track format of a variable length recording format. The figure shows a configuration example of one track. The track has one home address (hereinafter abbreviated as HA) 510 and one or more records 50.
It consists of 0. The HA 510 is a first field located at the head of each track, and includes information such as a track number. Each record 500 has one or more fields, that is, a count section 501 and a data section 502. A key unit (not shown) may exist before the data unit 502. The counting section 501 is a fixed-length field and stores information such as the address of the record 500 and the length of the following fields (the data section 502 and the key section). Each record 500 is allowed to have a variable length, that is, the length of the data section 502 may be different for each record 500. Therefore, the count part 501 includes the key part and the data part 50 of the record.
2 length is stored. By looking at the count section 501, the length of each field of the record 500 can be known. The address of the record 500 is indicated by a set of a cylinder number, a head number, a record number, that is, a sequential number assigned from the beginning of the track. Tracks are fixed length, but records are variable length,
The number of records included in each track is variable.

FIG. 4 is a schematic diagram showing a track format of a fixed-length recording format. In the fixed-length storage device, each track is composed of a predetermined fixed-length area (hereinafter, referred to as a block) 600. Each block 600 is uniquely numbered in the storage device. The access to a certain area of the storage device is performed by the number of the first block 600 of the area and the number of the subsequent block 6.
This is done by designating the number of 00.

FIG. 5 is an explanatory diagram showing an outline of format conversion from data of variable length recording format to data of fixed length recording format. Each track expressed in the variable-length recording format is converted into a fixed-length block 60 for format conversion.
It is divided into regions equal in size to zero. The head area of the head track indicated by the cylinder number 1 and the head number 0 is allocated to the head block 600 indicated by the number 0. Thereafter, when the subsequent area on the track is allocated to the subsequent block 600 and the entire area of the first track is allocated, the next track, that is, the head area of the track of cylinder number 1 and head number 1 is allocated to the subsequent block 600. Assigned. At this time, the count unit 501 of the variable length recording format is discarded without being stored.
Hereinafter, similarly, the entire area of each track is assigned to each block 60.
0. Cylinder number 0 stores volume information. If the mainframe volume 42 and the open system volume 43 have the same track format in the external storage device 4, the backup of the open system volume 43 from the mainframe 1 and the mainframe volume 4
The same data recording format conversion mechanism 141 can be used when backing up 2. Therefore, the track format of the mainframe volume 42 and the open system volume 43 should be the same. Since the data for the open system, for example, the SCSI data does not have a count section, the track format of the data for the main frame is adjusted to the track format of the data for the open system. That is, when a read request is issued from the mainframe side, the storage device control processor 1
The count section is generated by the data recording format conversion mechanism 141 of No. 4, and when a write request is issued from the main frame 1, the count section is discarded and only the data section is stored. Since the length of each track is a fixed length, the number of fixed-length blocks 600 in one track is determined by (track capacity / block capacity). From the track address, the number of the first block 600 storing the track can be obtained from “(cylinder number × head number + head number) × total number of blocks per track”.

When the data of the external storage device 4 is normally used from the open system 2, the open system 2
In response to a read request issued from the application program 212, data is read directly from the open system volume 43 of the external storage device 4. The backup of the mainframe volume 42 and the open system volume 43 existing in the external storage device 4 is performed as described below.

FIG. 6 is a flowchart of the backup processing of the main frame volume 42 by the main frame 1. In the backup processing of the mainframe volume 42, first, the backup software 112 of the mainframe 1 is started (step 1001).
The backup software 112 reads the backup data from the mainframe volume 42 (Step 1002). The read backup data is stored in the data recording format conversion mechanism 14 of the storage device control processor 14.
1, the data is converted from the fixed-length recording format to the variable-length recording format (step 1003). The data converted to the variable-length recording format is stored in the backup device 3 connected to the mainframe 1 (step 1004). The backup software 112 determines whether or not there is data to be backed up.
Steps 2 to 1004 are repeated to continue the backup process. If the backup of all data has been completed, the backup process is completed (step 100).
5).

The restoration of the backed up data
As with the backup process, the backup software 112
It is performed by The backup software 112 converts the backup data stored in the backup device 3 from the variable-length recording format to the fixed-length recording format by the data recording format conversion mechanism 141, and converts the mainframe volume 42.
To store.

FIG. 7 is a flowchart of the backup processing of the open system volume 43 by the mainframe 1. In the backup processing of the open system volume 43, first, all operations of the open system 2 using the backup acquisition target volume are stopped, and the volume 43 is unmounted (step 1301). The backup software 112 of the mainframe 1 is started. Backup software 1
In step 1302, the backup is started upon receiving from the user the designation of the volume serial number corresponding to the device file name of the volume 43 used in the open system 2 from the user. Hereinafter, step 10 described above
The backup is performed by the same processing from 02 to step 1005 (step 1303). When all data is stored in the backup device 3, the open system 2
, The mount processing is executed for the volume 43, and the business in the open system 2 is resumed (step 13).
04).

The restore process for the open system volume 43 is performed in the same manner as the mainframe restore process described above.

FIG. 8 is a flowchart of a process for backing up data in the open system volume 52 of the external storage device 5 to the backup device 3. Volume data in the external storage device 5 that cannot be directly accessed from the mainframe 1 is temporarily copied to the external storage device 4 and then stored in the backup device 3.

In the backup processing of the open system volume 52, first, a backup volume is created in the external storage device 43. The volume serial number and volume information of the backup volume are created by the volume list creation / data set allocation module 1121, and the cache memory 1
11 or stored in the external storage device 4. The backup volume, volume serial number, and volume information are created according to an instruction from the user (step 1401). Thereafter, in the open system 2, the data to be backed up is transferred to the open system volume 52 by a backup program or a system command of the open system 2.
To the backup volume of the external storage device 4. This process is called temporary backup. The copying performed here is performed, for example, on a file basis. At this time, a plurality of files are copied within the capacity of the backup volume (step 1402). After copying the backup data, the processing from the open system 2 is stopped, and the backup volume is unmounted from the open system 2 (step 140).
3). Subsequently, the backup software 112 of the mainframe 1 reads data by designating a backup volume. The data read from the backup volume is generated by the data recording format conversion mechanism 141 of the storage device control processor 14 in a simulated C section,
The fixed length recording format is converted to the variable length recording format (step 1404). The data converted to the variable length recording format is
Stored in the backup device 3 (step 140
5). After all the data of the files temporarily backed up to the backup volume are stored in the backup device 3, all the files copied to the backup volume are deleted to use the backup volume as the next primary backup destination (step 1).
406). The open system 2 mounts the backup volume 44 and makes the backup volume accessible from the open system 2 (step 1407). It is determined whether there is data to be backed up in the volume 52, and if there is still backup data, the processing from step 1402 is repeated. If there is no more data to be backed up in the volume 52, the backup process ends (step 1408).

The restoration of the backed-up data is realized by converting the variable-length recording format to the fixed-length recording format, passing the data to the open system 2 via the backup volume, and storing the data in the open system volume 52. .

FIG. 9 is a flowchart showing a second embodiment of the backup processing of the data of the open system volume 52 of the external storage device 5 to the backup device 3. In the processing illustrated in FIG. 9, the storage device control processor 14 determines the storage location of backup data from the volume information 431 and performs backup.
In this embodiment, the volume information for the backup data is created in the cache memory 111.

In the backup processing of the open system volume in the present embodiment, first, all the operations of the open system 2 using the open system volume 52 from which the backup is to be obtained are stopped.
After the business is stopped, the open system 2 executes unmounting of the volume 52 (or a command for each OS using the volume) (Step 1101). next,
The backup software 112 of the mainframe 1 is started (step 1102). The volume information creation / data set allocation module 1121 of the backup software 112 creates volume information and a volume serial number for the external storage device 5 connected to the open system 2 and stores them in the cache memory 111 in the main storage device 11. At this time, the cache memory 11
It is assumed that there is a virtual volume in 1. Here, the volume information is stored in the cache memory 111, but the volume information may be stored in another location. In order to facilitate operation, it is preferable that the device file name in the open system 2 be a name related to the volume serial number. Also,
The range of the volume serial number is determined in advance in the system so that it can be understood that the serial number corresponds to data in the external storage device 5. The volume serial number is managed and operated by the user (step 1103).

After creating the volume information, the backup software 112 requests the storage device control processor to read the backup data by designating the created volume information, and starts the backup process (step 1).
104). The recording device control processor 14 uses the volume serial number identification means 142 to determine whether or not the specified volume serial number is within the range of numbers for data in the external storage device 5. If the specified volume serial number is out of the range for the data in the external storage device 5, the open system volume of the external storage device 4 is backed up. Therefore, in this case, the same processing as step 1303 is performed (step 1105). If the specified volume serial number is within the range for the data in the external storage device 5, the recording device control processor 14 requests the open system 2 to read the data via the communication line 34. In response to this request, the open system 2
Starts the backup program, reads the backup data from the open system volume, and transfers it to the storage device control processor 14 via the communication line 34 (step 1106). Storage device control processor 14
Simulates the part C and converts it into a variable-length recording format so that the data transferred from the open system 2 can be used by the operating system 113 of the mainframe 1 by the data recording format conversion mechanism 141 (step 1107). ). The storage device control processor 14 sends the converted data to the operating system 113. The data sent to the operating system 113 is stored in the backup device 3 by the backup software 112 (step 1108). The storage device control processor 14 determines whether there is still backup data from the open system 2. If backup data remains, steps 1107 to 1108
Is repeated (step 1109). If the processing of all the backup data has been completed, the storage device control processor 14 reports the completion of the backup processing. The open system 2 executes the mount processing of the open system volume 53 and resumes the business (step 11).
10).

There is also a method of backing up data from the open system 2 after storing it to some extent.

At the time of restoration, the backup software 11
2, the backup data stored in the backup device 3 is read out, and is converted into a fixed-length recording format by the data recording format conversion mechanism 141. The storage device control processor 14 transfers the data converted into the fixed-length recording format to the open system 2 via the communication line 34. This data is restored to the open system volume 52 by the open system 2.

In the embodiment described above, the backup of the data stored in the volume of the external storage device 5 occupied by the open system 2 is realized by the interposition of the open system 2. Instead of the above-described method, it is also possible to connect the communication device 15 of the mainframe 1 to the communication device 35 of the external storage device 5 and perform backup without intervening the open system 2. In this case, as the backup preprocessing, the backup software 112 creates a volume serial number and volume information for the external storage device 5 (open system volume 52), and the cache memory 1
11 is stored. The backup processing can be realized in the same manner as the backup of the open system volume 43 described with reference to the flowchart of FIG. In the mainframe 1, in order to prevent erroneous access to the external storage device 5, the external storage device 5 is normally unmounted or the normal communication line 35 is off-line at normal times. Then, when the backup software 112 is activated, it can be connected to the external storage device 5.

FIG. 10 is a block diagram showing a configuration of a computer system according to still another embodiment of the present invention.
In the computer system according to the present embodiment, a mainframe 1, an open system 2, a backup device 3, and external storage devices 4, 5 are connected by an external storage device network 6. The external storage device network 6 and each device are connected by communication lines 34, 35, 36, 37, and 38. The mainframe 1, the open system 2, and the external storage devices 4, 5 are a communication device 1 for communicating with other devices via the external storage device network 6.
7, 25, 45 and 55 respectively. Normally, it is assumed that the external storage device 4 can be used from the mainframe 1, and the external storage devices 4 and 5 can be used from the open system 2. In the cache memory 111 of the mainframe 1, the volume serial number 114 and the volume information 11 for the open system volume 52 of the external storage device 5 created by the backup software 112 in advance of the backup processing are stored.
5 is stored.

In the backup processing of this embodiment, the backup data is transferred between the mainframe 1 and the corresponding external storage device and the backup device 3 via the network 6 between external storage devices. 7 can be realized by the same processing as the backup of the open system volume 43 described with reference to the flowchart of FIG.

According to the embodiment described above, in a computer system in which a mainframe and an open system are mixed, data such as a disk device connected to the open system and used by the open system is connected to the mainframe. Can be backed up to a backup device. In addition, since backup of open system data can be performed while taking it into the mainframe side, it is not necessary to create a backup volume in the external storage device on the mainframe side. Requires less storage capacity.

The present invention is not limited to the above embodiment. For example, the number of mainframes and open systems provided in the same system is not limited to one and may be two or more. Similarly, the number of external storage devices can be arbitrary.

[0040]

According to the present invention, in a computer system in which a mainframe and an open system coexist, when data used on the open system side is backed up to a backup device connected to the mainframe, a backup operation is performed. In this case, it is possible to reduce the area of the backup volume to be used for the backup and reduce the overhead of the backup operation.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a computer system according to an embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a logical configuration of an open system volume.

FIG. 3 is a schematic diagram showing a track format of a variable length recording format.

FIG. 4 is a schematic diagram showing a track format of a fixed length recording format.

FIG. 5 is an explanatory diagram showing an outline of format conversion from data in a variable-length recording format to data in a fixed-length recording format.

FIG. 6 is a flowchart of mainframe volume backup processing.

FIG. 7 is a flowchart of open system volume backup processing.

FIG. 8 is a flowchart of a backup process of data stored in an external storage device dedicated to the open system.

FIG. 9 is a flowchart according to another embodiment of a backup process of data stored in an external storage device dedicated to an open system.

FIG. 10 is a block diagram showing a configuration of a computer system according to still another embodiment of the present invention.

[Explanation of symbols]

1 ... Mainframe, 2 ... Open system, 3 ...
Backup device, 4, 5, external storage device, 13 communication device (variable length access interface), 15, 2
3, 41, 51: communication device (fixed length access interface), 14: storage device control processor, 42: volume for mainframe, 43, 53 ... volume for open system, 112 ... Backup software,
141: Data recording format conversion mechanism.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasutomo Yamamoto 1099 Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture Inside Hitachi, Ltd.System Development Laboratory (72) Inventor Takashi Oeda 1099 Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture Stock Company (72) Inventor Takahiko Shoyama 1 Horiyamashita, Hadano-shi, Kanagawa, Japan Enterprise Server Division, Hitachi Ltd.

Claims (8)

[Claims] 1. A first computer, a second computer, a first storage device connected to the second computer and storing data in a fixed-length recording format used by the second computer, and In an information processing system connected to the first computer and having a backup device for storing data in a variable-length recording format, a backup method for backing up data stored in the first storage device to the backup device is provided. Wherein the first computer requests the second computer to read the data in the fixed-length recording format, and in response to the request, the second computer causes the fixed storage format to be read from the first storage device by the second computer. The data in the long recording format is read and transferred to the first computer, and the data is transmitted to the first computer. Te, backup method, characterized in that said fixed-length data record format is converted into data of a variable-length record format and stores the data of the variable-length record format to the backup device. 2. The transfer step stores the fixed-length data read by the second computer in a second storage device connected to both the first computer and the second computer. 2. The backup method according to claim 1, wherein the fixed-length recording format data stored in the second storage device is read from the first computer. 3. An intermediate volume for copying the data of the fixed-length recording format in the second storage device,
3. The backup method according to claim 2, further comprising a process of creating volume information for identifying a start position and an end position of data held in the intermediate volume. 4. The backup method according to claim 3, wherein in the step of creating the volume information, the volume information is stored in a predetermined area formed on a main storage provided in the first computer. . 5. The fixed length recording format data is transferred via a communication line connecting the first computer and the second computer in the transferring step. Backup method. 6. Volume information for identifying a start position and an end position of the data of the fixed-length recording format in the first storage device is created, and the volume information is accessible from the first storage device. 6. The backup method according to claim 5, further comprising a process of storing data in a storage device. 7. The backup method according to claim 6, wherein said storing step stores said volume information in a predetermined area in a main storage of said first computer. 8. A fixed length recording format data which is connected to a first computer, a second computer, and both of the first computer and the second computer, and is used by the second computer. In an information processing system having a storage device and a backup device connected to the first computer and storing data in a variable length recording format, a backup for backing up data stored in the storage device to the backup device A method, comprising: storing volume information for accessing the data in the fixed-length recording format from the first computer in an area that is distinct from an area in which the data in the fixed-length recording format is stored; 1 computer, based on the information including the volume information, The first computer reads the data in the fixed-length recording format, converts the data in the fixed-length recording format into data in the variable-length recording format, and sends the converted data in the variable-length recording format to the backup device. A backup method characterized by storing.