JPH1124846A - Backup system using network - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the recording capacity and then to improve the reliability of data without increasing the number of backup devices by using the 1st communication networks, the 2nd communication networks which are connected in 1:1 to a host computer from plural clients, etc. SOLUTION: A 1st network 1 consists of the servers 15 to 17 having the auxiliary storage devices which record the history information on the recording media used by the backup devices 12 to 14 as data bases. This backup system includes the network 1, the 2nd to n-th networks 2, 3, etc., which are equivalent to the network 1, a host computer 9, the 2nd communication networks 11, etc. The computer 9 has the 1st communication networks 10, which are connected in 1:1 to all (n) pieces of networks to transfer the data to them. Then every network 11 is connected in 1:1 to the computer 9 so that the clients 4 to 8 can transfer the data to the computer 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backup system for recording data handled by a computer.

[0002]

2. Description of the Related Art Conventionally, one backup device used for storing data in a computer is arranged in one network, and only data in this network is backed up. Further, the management of the recording medium used in the backup device is performed only by recording the history information in a predetermined location of the recording medium itself, and the recording and reproduction of the history information is performed only when the recording medium is recorded and reproduced. Used only for equipment. Therefore, in the case of a network or an individual user who does not have a backup device, data is divided and backed up in a small-capacity storage device. Further, it is difficult to back up the same data in a distributed manner, so that there is a limit in data reliability.

[0003] This kind of problem is disclosed in Japanese Patent Laid-Open No. 4-281.
In Japanese Patent No. 245, the history information recorded in a predetermined portion of a recording medium is reproduced by a recording / reproducing device, and then stored in a RAM, and the history information stored in the RAM is updated each time the recording medium is used. Although the old history information is updated when the recording medium is taken out from the reproducing apparatus to improve the maintenance efficiency and the management reliability, no consideration is given to the simultaneous management of a plurality of recording media.

[0004]

In the above-mentioned prior art, although the data volume has been enlarged due to the recent spread of the Internet and the like, for example, private providers often do not have a large-capacity backup device.
Banks, securities companies, and the like do not have backup devices that secure a sufficient amount of data even though the data capacity is further increasing.

In such a case, the same data is currently performed using backup devices at two or more distant locations, but the above-mentioned two or more backup devices can be used exclusively. However, it is impossible to increase the number of backup devices in order to further secure data reliability.

[0006] Therefore, despite the increase in data, the available backup device is fixed and the available capacity is fixed.
Data reliability cannot be improved.

[0007]

In order to solve the above problems, a backup device for recording data handled by a computer and history information of individual recording media used in the backup devices (12 to 14) are recorded as a database. A first network (1) comprising servers (15 to 17) having auxiliary storage devices, and second, third,..., N-th networks (2,
3) a host computer (9) having a first communication network (10) connected one-to-one so that data can be transferred to all of the n networks, and Client (4 ~
The backup system uses a network composed of a second communication network (11) connected one-to-one so that data can be transferred from 8).

Second, when the host computer (9) receives a backup request from the client (4 to 8), the server (15 to 17) of the first to n-th networks (1 to 3) manages it. A backup system using a network that refers to the history information database.

Third, the host computer (9) selects and selects the backup devices (12 to 14) of the first to n-th networks (1 to 3) based on the result of referring to the history information database. A backup system using a network that sends a backup command to a backup device is used.

Fourth, the host computer (9) performs a backup using a network that refers to the number of accumulated write frames, the number of accumulated write error blocks, the number of accumulated read error blocks, and the number of loadings recorded in the history information database. System.

Fifth, the clients (4 to 8) select backup types provided by the host computer (9) to provide the backup devices (12 to 14) used in the first to n-th networks. On the other hand, a backup system using a network capable of distributing and recording data is used.

Sixth, the client (4-8) is a backup system using a network via the host computer (9) when backing up data.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a connection example when the backup device of the present invention is used in a network environment. Reference numeral 1 denotes an auxiliary storage device 15 in which a history information database is recorded in a first network, and a backup device 1
2, a server 18 and a plurality of clients. The server 18 is connected to the plurality of clients and the backup device 12.

The backup device 12 is connected to the server 1
Recording and reproduction of data are performed according to the instruction of No. 5. The history information of each recording medium is read from the auxiliary storage device 15, updated in the memory of the server 18, and when the recording medium is taken out of the backup device, the history information in the memory is written to the auxiliary storage device. Do. For a newly used recording medium, history information is generated in the memory, and is similarly written to the auxiliary storage device when the recording medium is taken out.

Reference numerals 2 and 3 denote second and third networks having the same configuration as the first network.

Reference numerals 4, 5, and 6 denote fourth, fifth, and sixth networks having no backup device. A network is configured for a plurality of clients, each centering on the servers 21, 22, and 23. Computers 7 and 8 have no backup device.

Reference numeral 9 denotes a host computer, and reference numerals 10 and 11 denote first communication means and second communication means, respectively. The host computer 9 is connected to the first to third networks 1, 2, 3 by the first communication means 10 and the fourth to sixth networks 4, 5, 6 by the second communication network 11. 7 and 8 are connected so that data communication is possible.

Further, when viewed from the host computer 9,
The network and the computer 8 are the backup requesting side and the client, and the networks 1 to 3 are the backup side for the client's backup request.

In the figure, a fourth network having no backup device sends a backup request to the host computer 9, and the host computer 9 receiving the request selects a third network having a backup device, and 4 shows a case in which data of the fourth network is backed up to the server 20 of the fourth network by using a backup device.

FIG. 2 is a block diagram showing a procedure when the fourth network backs up data using the backup device of the third network in the connection example shown in FIG.

A switch 21 for issuing a backup request to the host computer 9 is provided for explanation. Reference numeral 22 denotes a switch for selecting a backup mode, which is provided for explanation. Changeover switch 21,
Switching of 22 is performed by the fourth network. The figure shows that the fourth network issues a backup request to the host computer 9 using the changeover switch 21, and switches the mode to change over the switch 22 to perform data backup as the first form of backup.

Reference numeral 23 denotes a changeover switch for reading a database managed by a server on the first to third networks. The authority of the switch changeover belongs to the host computer 9.

Here, the backup mode is a selection of the number of backup apparatuses to be used. In this example, the backup mode 1 is one backup apparatus, the backup mode 2 is two backup apparatuses, and the backup mode 3 is three backup apparatuses. Although the apparatus is used, this is not always the case when there is a difference in the network connection form or the service form of the host computer 9.

The host computer 9 which has received the backup request using the backup mode 1 from the fourth network reads the history information database managed by the first to third networks using the first communication means 10. As a result of the reading, the capacity and reliability for data backup are confirmed, and a backup device and a recording medium according to the backup mode 1 are selected.

Next, with reference to FIG. 3, a process for selecting a backup device depending on a difference in the backup mode will be described with reference to a flowchart.

When a backup request is issued to the host computer 9 from a network, a computer or the like having no backup device (process 1), the host computer 9 determines the backup mode by inquiring the source of the request about the backup mode. (Process 2).

Thereafter, a constant value according to the backup mode is determined (process 3). Next, the host computer 9 connects to the network having the first backup device (process 4) and refers to the history information (process 5). Refers to the managed history information database.

The capacity and reliability are confirmed from the history information (decision 2). If the determination result is satisfied, the backup device having the history information currently being referred to is recognized (process 6), and if not satisfied, it belongs to the network having the next backup device (process 7). When a backup device conforming to the backup mode is recognized, a backup command is sent to the server having the backup device (process 8). Thereafter, a transfer permission for the backup data is sent to the backup request source (process 9).

FIG. 4 is a flowchart showing the details of (judgment 2) shown in FIG. (Process 1) is access to a network having a backup device for reading the history information database at the start of the recording medium search.

In the history information database, history information on individual recording media is collected and recorded in the auxiliary storage device of the server. Therefore, after confirming that the history information is not the last history information constituting the history information database (decision 1). ),
The first history information is read into the memory of the host computer (Process 2). Information indicating the number of loadings, the number of cumulative write frames, the number of cumulative read frames, the number of cumulative write error blocks, and the number of cumulative read blocks is extracted from the read history information (process 3). A write error rate and a read error rate are calculated using the extracted information, and an average of both is set as an error rate of the recording medium having the history information (process 4).

Next, in order to verify the reliability of the recording medium, it is confirmed that the error rate and the number of times of loading satisfy a set threshold value (decision 2). Here, the set threshold value is for securing a margin of reliability, and can be arbitrarily set by an administrator of the host computer as long as it exceeds the specification value of the recording medium. Loading times,
If the error rate value is satisfied, in order to check the recording capacity of the recording medium, the sum of the backup data and the cumulative number of write frames requested by the client is equal to or less than the total recording capacity of the recording medium multiplied by the error rate. Confirm that there is (determination 3). The reason why the total recording capacity is multiplied by the error rate is to allow for the error rate of the unrecorded portion.

The read history information is (judgment 1,
When 2) is satisfied, it is recognized that the recording medium having this history information can be used for backup. On the other hand, a recording medium having history information that cannot satisfy (determination 1) or (determination 2) is determined to be unusable for backup, and the host computer reads the next history information from the history information database (process 5). When the history information constituting the history information database becomes the last, the process is terminated. Here, if the capacity cannot be recorded by one recording medium, the number of recording media to be used is calculated in advance by dividing the backup by the maximum recording capacity of the recording media, and then the recording media that satisfies the number are selected. I do.

FIG. 5 is a block diagram showing the flow of backup data when the fourth network backs up data using the backup device of the third network in the connection example shown in FIG. 24,2
Reference numerals 5 and 26 denote switches for transferring data, which are located in the middle of the first communication network 10 and are switched by the host computer 9.

There are three types of backup modes for the host computer 9. Here, the first mode corresponds to one backup apparatus, the second mode corresponds to two backup apparatuses, and the third mode corresponds to three backup apparatuses as described above. It is. The changeover switches 24, 25, and 26 are respectively connected to the backup modes 1 to 3. In the case of the mode 1, any one of the three switches can be switched.
Any two of the three switches can be switched, and in the case of mode 3, all three switches are used. Reference numeral 27 denotes a switch for conducting control signals of the changeover switches 24, 25, and 26. In the case of □, the changeover switch is turned off, and in the case of ■, the changeover switch is turned on.

In the figure, the signal output from the backup mode 1 turns on the switch 26. As a result, the fourth network issues a "data backup request in the backup mode 1" to the host computer 9, and as a result, the host computer refers to the history information of the backup devices 12, 13, and 14 to allow the third network This means that the backup device 14 having the backup is selected. After selecting the backup device, the host computer 9 issues a command “Transfer data to be backed up” to the fourth network, and the fourth network receiving the command sends the command to the host computer 9.
Transfer data to The transferred data is recorded in the backup device 14 because the switch 26 is turned on.

[0036]

As described above, the present invention is used for backing up data using a network, so that the recording capacity can be increased without adding a backup device, and the reliability of data can be increased by dispersing the data. It is possible to improve the performance.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a network for explaining the present invention.

FIG. 2 is a block diagram showing a procedure for backing up data.

FIG. 3 is a flowchart showing processing for selecting a backup device.

FIG. 4 is a flowchart showing processing for selecting a used recording medium.

FIG. 5 is a block diagram showing the flow of backup data.

[Explanation of symbols]

1 ... first network, 2 ... second network,
3 ... the third network, 4 ... the fourth network,
5 ... fifth network, 6 ... sixth network,
7 ... computer, 8 ... computer, 9 ...
Host computer, 10 means for first communication, 11
... Second communication means, 12, 13, 14 ... Backup device, 15, 16, 17 ... Auxiliary storage device, 18,1
9, 20, 21, 22, 23 ... server.

Claims (4)

[Claims] 1. A backup device (12-14) for recording and reproducing data handled by a computer, and an auxiliary for controlling the backup device (12-14) and recording history information of individual recording media used for recording and reproduction as a database. A first network (1) comprising servers (16-18) having storage devices (15-17), and second, third,..., Nth networks (2,3) equivalent to the first network ), A host computer (9) having first communication means (10) connected one-to-one so that data can be transferred to all of the n networks, and a plurality of clients for the host computer. (4 ~
8) A backup system using a network, comprising a second communication means (11) connected one-to-one so that data can be transferred. 2. When the host computer (9) receives a backup request from the client (4-8), the server (15-17) of the first through n-th networks (1-3) manages it. Reading the history information database, comparing the history information data for each recording medium with predetermined data, determining a server and a recording medium based on the comparison result, and sending a backup command to the server. A backup system using the network according to claim 1. 3. The first computer according to claim 1, wherein
2. The network-based backup system according to claim 1, wherein data from the client is distributed and recorded in backup devices (12 to 14) used in the first to n-th networks. 4. The backup system using a network according to claim 1, wherein the clients (4 to 8) backup the data via the host computer (9).