JP2000148404A - Computer system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To write the archive data into a disk subsystem with no intervention of a host by providing a resettable WORM function which recognizes and manages the archive data in the disk subsystem with no intervention of the backup software of a host computer. SOLUTION: A CPU 1 issues a write command group N to a single LDEV 9 and meanwhile a resettable WORM function reads a written flag and then executes a writing operation to a record after confirming that this writing operation is not over yet. Then the CPU 1 issues a write command group M to a single LDEV 9 and the WORM function reads a written flag and reports a write unable state to the CPU 1 after confirming that a writing operation is already over. Thus, it's possible to cope with the larger capacity of the archive data and also to deal with the performance and extensibility in a computer system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a computer system, and more particularly to a WORM function (one-time writing, multiple writing) capable of resetting data on one or a plurality of disk subsystems directly accessed by a host. Read function), and writes archive data to a disk subsystem without the intervention of a host.

[0002]

2. Description of the Related Art In a computer center (hereinafter referred to as a computer center) for performing business processing, there are two main methods for storing archive data in an appropriate archive storage device for the purpose of long-term storage as follows. The scheme has been adopted.

The first method is to write target archive data to a magnetic tape device or a magnetic tape library device using backup software of a host.

The second method is to write target archive data to an optical disk device or an optical disk library device using backup software of a host.

[0005] In both the first and second systems, writing of archive data cannot be executed without backup software. This is because the backup software recognizes and manages the data archive state. That is, the backup software can recognize whether or not the archive data has been written in the archive storage device. If the archive data has already been written, it is not necessary to write the data twice.

[0006]

The first method described above is based on:
In order to use a magnetic tape device as an archive storage device,
There is a concern about low performance when writing archive data to a medium and performing random access to the data.

The second method uses an optical disk device as an archive storage device, and therefore has higher random access performance than a magnetic tape device in performance, but is lower than a magnetic disk device. Further, the conventional optical disk device has WORM characteristics and allows only one write, so that it is impossible to reuse the recording area.

In both the first and second systems, backup software running on the host is required, so that the cost of implementing the system is large. In addition, since the processing of the backup software is borne by the host, the load on the host increases and there is a concern that the performance of normal business processing may be affected.

[0009]

In order to solve the above-mentioned problems, the present invention mainly employs the following configuration.

A computer system having a disk subsystem for writing archive data from a host computer, which can recognize, manage and set archive data in the disk subsystem without going through backup software of the host computer. It has a WORM function.

In the resettable WORM function, writing is performed on a record of a logical volume and a written flag of the record. When writing is performed, the written flag is read. It has a WORM function that allows writing and resetting when writing has not yet been performed.

In the resettable WORM function, when a logical volume to be written in a disk subsystem becomes full, archive data can be recorded in an archive storage device such as a magnetic tape library device. It has a resettable WORM function that puts it in a resettable state.

In the resettable WORM function, it is sensed that archive data has been recorded in an archive storage device such as a magnetic tape library device from a full logical volume of a disk subsystem, and all data in the logical volume has been written. It has a resettable WORM function that can set an embedded flag in an unwritten state.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example in which the present invention is applied to a general-purpose computer system will be described with reference to the drawings.

FIG. 1 shows an example of the configuration when the present invention is targeted for archiving in a general-purpose computer system.
The data is archived by using a resettable WORM function having a control mechanism different from that of the CPU without using the backup software.

In FIG. 1, reference numeral 1 denotes a CPU which is a central processing unit (host computer). Reference numeral 3 denotes a CPU which is connected to the CPU 1 via a channel interface cable 2.
Is a disk subsystem (hereinafter referred to as DISK) that stores data to be referenced and updated directly from the server.

Next, the disk control device 4 (hereinafter referred to as DKC) and the disk drive device 8 (hereinafter referred to as DK
U) Each internal configuration will be described. In the DKC 4, reference numeral 5 denotes a channel interface control unit (hereinafter, CHD) for controlling the exchange of control information such as a data read / write instruction of the CPU 1, and reference numeral 6 denotes a data interface between the CPU 1 and the logical volume 9 (hereinafter, LDEV). reading·
When writing, a cache memory (hereinafter referred to as a cache), which is used to buffer data once,
A disk interface control unit (hereinafter, DID) that controls a process of writing data to the LDEV 9.

Reference numerals 11 and 12 denote a magnetic tape control device 11 and a magnetic tape device (library) 12 used for expanding the capacity of archive data, and are connected to the CHD 5 via an archive interface cable 10. In the present embodiment, a magnetic tape device (library) including a tape volume or the like will be described below. However, the present invention can be applied to other archive storage devices. Another role of the CHD 5 is to recognize and manage recording of archive data from the LDEV 9 to a magnetic tape device (library).

The above is the system configuration for realizing the functions of the present invention.

Next, a resettable WORM function according to this embodiment will be described with reference to FIG. CPU1
The write command group N is issued to the single LDEV 9, and the WORM function capable of resetting the write command group N first reads the written flag, and after confirming that it is (0), that is, confirms that writing has not yet been performed, the record N Write to Next, the CPU sets the write command group M
Is issued to the single LDEV 9, the WORM function which can be reset first reads the written flag, confirms that this is (1), that is, the write has already been performed, and then changes the state of the write disable to the CPU 1. Report to

Next, the operation of the resettable WORM function (in the case where there is no magnetic tape device (library)) in this embodiment will be described with reference to FIG. CPU1 is CH
The host command group is issued to D5, and the CHD5 receives the host command group and first checks whether or not the command is an LDEV data reset command. The LDEV data reset command is used to empty the LDEV after recording the archive data in the archive storage device from the LDEV filled with the archive data.

If the host command group is an LDEV data reset command, DID7 is
The data of the DEV 9 (including the written flag) is deleted, and the CHD 5 waits for the next host command group. If the host command group is not an LDEV data reset command, the CHD 5 checks whether the host command group is a host command group for writing data. If the host command group is not a host command group for writing data, after executing an operation corresponding to the host command,
The HD 5 waits for the next host command group.

If the host command group is a host command group for writing data, the CHD 5 reads the written flag at the write location specified by the host command group. If the written flag is (0), DI
D7 writes the archive data to the record, sets the written flag of the record to (1), and CHD5 waits for the next host command group. If the written flag is (1), the CHD 5 reports a command reject (write disabled) to the CPU 1 and waits for the next host command group.

In the resettable WORM function of the computer system as described above, the exchange in the data transfer control between the CHD 5 and the magnetic tape controller 11 is as follows.
This is performed by using a command similar to a command word (command) used in controlling data transfer between a general host computer and a magnetic tape control device.

[0025]

According to the present invention, the disk subsystem itself is provided with a resettable WORM function so that archive data can be written to the disk subsystem without the intervention of a host. Performance can be improved.

Further, a magnetic tape device (library) is added to a disk subsystem having a resettable WORM function.
By connecting, the capacity of the archive data can be increased, and the performance and expandability can be supported.

Further, no resources on the host side are used for the recognition and management of archive data, and there is no reduction in the CPU's business processing capacity due to the construction of backup software for the CPU.

[Brief description of the drawings]

FIG. 1 shows a resettable WO in one embodiment of the present invention.
The figure which shows the system configuration of an RM function.

FIG. 2 is a diagram showing written flags and records during operation in the disk subsystem of the WORM function according to the present invention.

FIG. 3 shows a resettable W of a disk subsystem [without a magnetic tape device (library)] according to the present invention.
9 is a flowchart of the operation of the ORM function.

[Explanation of symbols]

1 CPU, 2 channel interface cable, 3
... Disk subsystem (DISK), 4 ... Disk control unit (DKC), 5 ... Channel interface control unit (CHD), 6 ... Cache memory, 7 ... Disk interface control unit (DID), 8 ... Disk drive unit (DKU) , 9 ... logical volume (LDEV), 10 ...
Archive interface cable, 11: magnetic tape controller, 12: magnetic tape device (library).

Claims (3)

[Claims] 1. A computer system comprising a host and a disk subsystem, wherein the disk subsystem itself has a resettable WORM function and writes archive data to the disk subsystem without going through the host. 2. The computer system according to claim 1, further comprising an archive storage device such as a magnetic tape library device, wherein the archive data written in the disk subsystem itself is stored in the computer system.
A computer system for writing to an archive storage device without going through a host. 3. The computer system according to claim 2, wherein the writing of the archive data written in the disk subsystem itself to the archive storage device is guaranteed only once. .