JP4371756B2 - Data backup method and backup device - Google Patents

Description

  The present invention relates to a data backup method and backup system in a computer system, and more particularly to a data backup method and backup system with improved read characteristics to a backup device.

  In general, a business computer system is connected to, for example, a plurality of magnetic disk devices and backs up data stored in the plurality of magnetic disk devices to another backup device (magnetic tape storage device, etc.) in order to cope with a disaster or the like. A backup device is connected. The data transfer between the computer system and the backup device is performed between the buffers, and the backup device issues a read command specifying the data transfer length to the target (magnetic disk device) of the computer system. Was done by doing.

In addition, as a document in which the technique regarding the data backup in a computer system was described, the following patent document 1 is mentioned, for example.
JP 2003-208355 A

  However, the data backup according to the prior art is fixed in consideration of the read characteristics of each target because the data transfer length is fixed regardless of the target type by the read command issued from the backup device to the target. There was a problem that became redundant.

  More specifically, suitable read characteristics depending on the target type vary depending on the cache memory capacity, data transfer speed, I / F circuit characteristics, etc. of the magnetic disk device. For example, the data transfer length is 256 Kbytes. / 2048 Kbytes / 4096 Kbytes is assumed, but the maximum read characteristic of target A is 50 Mbytes / second with 4096 Kbytes, the maximum read characteristic of target B is 50 Mbytes / second with 256 Kbytes, and the maximum read characteristic of target C is 2048 K When the data transfer length is set to 4096 Kbytes, for example, when the data transfer length is set to 4096 Kbytes, the transfer efficiency is improved in the target A, but the transfer efficiency is lowered in the other targets B and C, and the backup time as a whole There was a problem that became redundant.

  The present invention eliminates the problems caused by the prior art described above, and sets data transfer length suitable for each target to improve the read characteristics as a whole and to reduce the backup time. A backup method and a backup apparatus are provided.

  In order to achieve the above object, the present invention provides a data backup method for a backup device that backs up data of a computer system having a plurality of targets by designating a data transfer length, wherein the backup device includes a plurality of targets for a plurality of targets. A first step of dummy-reading data from the target by designating a data transfer length, a second step of measuring data transfer efficiency at the time of dummy read in the second step, and a plurality of targets measured in the second step Of the data transfer efficiencies corresponding to a plurality of data transfer lengths, a third step of storing the data transfer length obtained with the highest data transfer efficiency of each target, and the highest data transfer efficiency corresponding to each target stored in the third step And a fourth step of transferring data with the obtained data transfer length. In this data backup method, the data transfer efficiency, and second, characterized in that the transfer time to transfer the data transfer amount, or a predetermined data transfer within a specified time factor.

  Furthermore, the present invention provides a backup device for backing up data of a computer system having a plurality of targets by designating a data transfer length, a data transfer set value storage area for storing a data transfer length read from the target, A buffer for temporarily storing the read data; and a data transfer efficiency measuring means for measuring the data transfer efficiency specifying the data transfer length stored in the data transfer set value storage area. The data transfer length of the target is dummy-read from the target to the buffer, and the data transfer efficiency is measured by the data transfer efficiency measuring means at the time of the dummy read. Of the corresponding data transfer efficiency, A data transfer length obtained with high data transfer efficiency is stored in the data transfer set value storage area, and data transfer is performed with the data transfer length obtained with the stored maximum data transfer efficiency corresponding to each target. In this data backup device, the data transfer efficiency is characterized in that a factor is a data transfer amount within a predetermined time or a transfer time during which the predetermined data transfer amount is transferred.

  The data backup method and backup device according to the present invention perform dummy read designating a plurality of data transfer lengths for each target, measure the data transfer efficiency during this dummy read, and obtain the maximum data transfer efficiency of each target. Since data backup is performed using the data transfer length, the read characteristics as a whole can be improved and the backup time can be shortened.

  Hereinafter, an embodiment of a data backup method and a backup apparatus in a computer system according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram for explaining a computer system and a backup device to which a backup method according to this embodiment is applied, and FIG. 2 is a diagram for explaining a backup device according to this embodiment.

  As shown in FIG. 1, a computer system that is an object of this embodiment includes a CPU 1 that performs information processing, a memory 12 that temporarily stores data and programs, and a plurality of targets that are magnetic disk devices that record various data. 13a to 13c, a buffer 14 for temporarily storing data when data is transferred from the targets 13a to 13c to the backup device 20, and a peripheral device such as a display unit / printer (not shown). The buffer 14 may be a cache memory built in each of the targets 13a to 13c.

  Now, the backup device for performing the backup method according to the present embodiment includes a backup device 27 such as a magnetic tape device for storing and backing up the data transferred from the plurality of targets 13a to 13c, and the data of the data according to the present embodiment. A backup control unit 21 for controlling backup, the backup control unit 21 temporarily storing data transferred from the buffer 14 of the computer system 10, and a unit time for the data transfer A data transfer counter 25 for measuring the amount of data per hit, a timer 24 for measuring a transfer time of a predetermined amount of data, a backup target list storage area 22 for storing a list of targets 13a to 13c to be backed up, Data for each target Maximum data transfer efficiency in which dummy read (dummy backup) with a changed transfer length is performed, and the measured value by the data transfer counter 25 is the shortest time and the data transfer time by the timer 24 is short for each target 13a to 13c The data transfer set value storage area 23 for storing the obtained data transfer length and a control unit (not shown) are provided. Note that the measurement by the timer 24 and the counter 25 corresponds to the data transfer efficiency measuring means.

  The computer system and the backup device configured as described above have three types of data transfer of a plurality of transfer data lengths, for example, 256 Kbytes / 2048 Kbytes / 4096 Kbytes, for example, for the target 13a during initial installation or tuning of the backup device The length is set, and three dummy reads are executed to transfer the data of the target 13a to the buffer 26 via the buffer 14, and per unit time corresponding to each data transfer length at the time of the three dummy reads. Is measured by the data transfer counter 25, the transfer time of the predetermined data amount is measured by the timer 24, the maximum data transfer efficiency, for example, the measured value by the data transfer counter 25 is the shortest time, and the data transfer by the timer 24 is performed. Data transfer length for a short time Stored in the transmission setting value storage area 23, similarly for other target 13b and 13c, and stores the data transfer length with the highest data transfer efficiency for each target in the data transfer set value storage area 23.

  More specifically, as shown in FIG. 2, this processing designates a target to be backed up (step 31), sets a data transfer length for the designated target (step 32), and then The presence / absence of a specified number of issuance commands specifying tuning is determined (step 33). When there is no specified number of issuance commands in step 33, a read command is issued (step 34), and then the process returns to step 33. When it is determined that there is a designated number issuance command, it is determined whether or not the measured value by the data transfer counter 25 and the timer 24 has the highest data transfer efficiency (step 36), and the highest data transfer efficiency is determined. When this occurs, the data transfer length is temporarily stored (step 37), and the maximum data transfer efficiency cannot be achieved. Sometimes the process proceeds to the next step 38.

  Next, in this process, it is determined whether or not there is another data transfer length in step 38. If there is another data transfer length in step 38, the process returns to step 33 to perform measurement with the other data transfer length. When there is no other data transfer length in step 38, the data transfer length temporarily stored in step 37 is stored in the data transfer set value storage area 23 (step 39), and the highest data transfer length is stored for all targets. It is determined whether or not the data transfer length has been measured (step 40). If there are remaining targets, the operation returns to step 31 to measure other targets, and the process is terminated.

  As described above, the data backup method and the backup apparatus according to the present embodiment perform dummy read for designating a plurality of data transfer lengths for each of the targets 13a to 13c and transferring them to the buffer 26, and at this dummy read, the data transfer counter 25 Then, the timer 24 measures the maximum data transfer data length and operates so as to store it corresponding to each of the targets 13a to 13c.

  Next, in the data backup method and the backup device according to the present embodiment, when the backup of data stored in each of the targets 13a to 13c of the computer system is instructed by the user, the backup device shown in FIG. By specifying the maximum data transfer length stored in the data transfer set value storage area 23 for each target and performing backup, the read characteristics of the entire system can be improved and the backup time can be shortened. it can.

  Note that the data backup method and backup system of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, the data transfer efficiency can be measured by either the data transfer time per predetermined amount of data by the timer 24 or the data transfer amount per predetermined time by the data transfer counter 25, or the highest data transfer efficiency by other methods. The data transfer length may be set every predetermined maintenance period, when a new target is added to the computer system, or when the system is started up.

The figure for demonstrating the computer system and backup device to which the backup method by this invention is applied. The figure for demonstrating the backup device by this embodiment.

Explanation of symbols

10: computer system, 12: memory, 13a to 13c: target, 14: buffer, 20: backup device, 21: backup control unit, 22: backup target list storage area, 23: data transfer set value storage area, 24: timer 25: Data transfer counter, 27: Backup device.

Claims (4)

A data backup method for a backup device for backing up data of a computer system having a plurality of targets by specifying a data transfer length,
A first step in which the backup device performs a dummy read of data from a target by designating a plurality of data transfer lengths for a plurality of targets; a second step of measuring data transfer efficiency at the time of dummy read in the second step; A third step of storing a data transfer length that obtains the highest data transfer efficiency of each target among the data transfer efficiencies corresponding to a plurality of data transfer lengths for each of the plurality of targets measured in the second step; And a fourth step of transferring data with a data transfer length obtained with the highest data transfer efficiency corresponding to each target stored in the step. 2. The data backup method according to claim 1, wherein the data transfer efficiency is based on a data transfer amount within a predetermined time or a transfer time during which the predetermined data transfer amount is transferred. In a backup device that backs up data of a computer system having a plurality of targets by specifying a data transfer length,
A data transfer set value storage area for storing the data transfer length read from the target, a buffer for temporarily storing data read from the target, and a data transfer length stored in the data transfer set value storage area are specified. Data transfer efficiency measuring means for measuring the data transfer efficiency, and by designating a plurality of data transfer lengths for a plurality of targets, data is dummy-read from the target to the buffer, and the data transfer efficiency at the time of the dummy read is Measured by the data transfer efficiency measuring means, and the data transfer set value storing the data transfer length obtained from the maximum data transfer efficiency of each target among the data transfer efficiencies corresponding to the plurality of measured data transfer lengths for the plurality of targets. Store in the area and store the highest data transfer efficiency for each target Performing data transfer with the data obtained transfer length data backup apparatus according to claim. 4. The data backup apparatus according to claim 3, wherein the data transfer efficiency is based on a data transfer amount within a predetermined time or a transfer time during which the predetermined data transfer amount is transferred.

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