JP2001134456A - Automatic operation continuing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure high availability related with the failure of a system constituted of two host computers and two outside storage devices. SOLUTION: The failures of a host computer 100 and an outside storage device 150 are communicated to a host computer 110 or discovered by the host computer 110 itself through an LAN interface 600 and an SCSI interface or fiber channel interface 510. When the failure is discovered, an outside storage device 160 is changed to an available state so that the processing can be continued. Also, when the host computer 100 and the outside storage device 150 are restored, the restoration is detected by the host computer 110, and the duplication of a volume 210 of the outside storage device 160 to a volume 200 is instructed to an outside storage device 150, and when the duplication is ended, the processing is transferred to the host computer 100 and the outside storage device 150.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a system comprising a computer device and an external storage device connected to the computer device.

[0002]

2. Description of the Related Art Due to a demand for reliability of non-stop operation and non-stop maintenance of a database or the like, it is necessary to shift processing to a standby system in the event of a failure of an active computer or an external storage device due to a disaster or the like.

[0003] When a failure occurs in the active system, the cluster switch automatically switches to the standby system and the host computer uses the data copy of the external storage device of the standby system to continue processing. The process of switching to the active system is generally performed manually by judging the state of the external storage device and the host computer. In this case, the switching of the processing system cannot be automatically executed, so that much time must be spent for the switching and data recovery.

Japanese Patent Laid-Open No. Hei 5-189167 describes a method for automatically recovering from a disk failure.

[0005] In this method, recovery using a program is possible, but it is not possible to perform arbitration of the states of a plurality of host computers and external storage devices and to switch between processing systems for recovery or recovery.

[0006]

As a recent market trend, a demand for a multipurpose server to which a highly reliable external storage device is connected has been increasing. Since a plurality of disk images can be shown to a client, it is required to deal with transaction processing for important data with high reliability. for that purpose,
Immediate measures are required for failures of the external storage device and the host computer. The automatic operation transition, the restoration of the computer, the external storage device, and the data in the external storage device, and the re-transition to the active system after the data restoration.

However, in the prior art, it is difficult to perform quick recovery because there is a waiting time due to a reason such as manual intervention in data recovery at the time of re-migration and inability to access a volume at the time of recovery.

[0008]

Means for Solving the Problems Conventionally performed manually by a proper judgment when switching from the active system to the standby system and returning when the active system is restored, the processing of the host computer and the external storage device While the status is monitored by the coordination of the functions, when the status is changed, the operating host computer and external storage device automatically determine and execute appropriate processing as appropriate, so that the operation is automatically continued. Perform operation migration and operation recovery.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the external storage device according to the present invention will be described.

FIG. 1 shows the entire system according to the present embodiment.
FIG. 3 is a diagram showing a configuration.

This system is composed of a host computer (100-11).
0) and external storage devices (150-160) connected to them. Host computer (100-110) is an external storage device
(150-160) and SCSI or Fiber Channel interface (510-520)
110) are connected by a LAN interface (600), and the external storage devices (150-160) are connected by an ESCON interface (500), and can communicate with each other. The host computer (100) executes a program (300) for monitoring the host computer (110) and the external storage device (150) that are to be paired with each other using communication. ) Can be instructed to a server program such as a database or an external storage device management program (400) executed on the server. The discovery of a failure of the host computer (110) is judged by the success or failure of communication with the host computer (110) on a regular basis, so that the operating host computer (100-110) can ensure data consistency. An instruction is given to the external storage device (150-160) and the volume (200-160) between the external storage devices (150-160) is given.
Change the state of duplication of 210). External storage device (150-
160) also monitors the state between the external storage devices (150-160),
Management of creation of a copy of the volume (200-210) between the external storage devices (150-160), interruption of the copy, and external storage device (150-160)
When a failure occurs, data difference management is performed to maintain data consistency between the original volume and the duplicate volume.

When a failure occurs in the active host computer (100), the monitoring program (310) on the standby host computer (110) is used by the active host computer (10).
0), the response from the monitoring program (300) disappears, and the external storage device management program (410) stores the volume (210) of the standby external storage device (160) in the active volume (2).
From the duplication operation from 00), release is instructed. The external storage device management program (410) transmits a disconnection instruction to the external storage device (160) by using a communication function with the external storage device (160). When the release is confirmed by the external storage device management program (410), the processing is transferred to the monitoring program (310), the standby server program is started using the volume (210) that has become available, and the server program is switched to the log standby system. The process is continued by referring to the log that has been replicated.

When the standby system monitoring program (310) confirms that the active system host computer (100) has recovered and the active system monitoring program (300) has been operated, the standby system monitoring program (310) changes to the standby system monitoring program (310). External storage device management program
Instruct (410) to perform reverse replication to the active volume (200) to be restored from the standby volume (210) in use. The standby external storage device management program (410) verifies that the active volume (200) is available through the active external storage device management program (300), and stores the standby type in the external storage device (160). Is instructed from the volume (210) to the active volume (200). When the standby external storage device management program (410) confirms that the replication has been completed, the volume is transferred to the standby system monitoring program (310).
Tell the recovery of (200). The standby type monitoring program (310) receives this and notifies the active type monitoring program (300) that it can be restored to the active type. Active system monitoring program
In response to the request, (300) instructs the stop of the standby server program, the change to the volume use state of the active external storage device (150), and the activation of the active server program. The active system switches the operation to the active system in the same process as after the standby system.

When a failure occurs in the standby system, the external storage device (150) of the active system suspends duplication, and the operation continues in the active system. When the standby external storage device (160) is restored, the external storage device management program (410) of the standby host computer (110) detects and informs the active external storage device management program (400). Based on the report from the active external storage device management program (400), the active system monitoring program (300) suspends the processing of the active system server program and temporarily changes the volume of the active system (200) to the volume of the standby system (210). ) Is issued to the active external storage management program (400).

An active external storage device management program (40
0) changes the status of the active system and standby system volumes (200-210) to the replication status. After confirming the change to the replication state,
The active monitoring program (300) resumes processing of the active server program. The server program continues processing by referring to the log restored to the active system.

By introducing this system, it becomes possible to automatically shift the operation of the server program at the time of failure and to shift the operation again at the time of recovery.

[0017]

According to the present invention, in a system in which two host computers and two external storage devices are connected,
The user of the server program can perform processing using the server without being aware of the state of the system, thereby improving the availability of the entire system.

[Brief description of the drawings]

FIG. 1 is a configuration diagram in this system.

[Explanation of symbols]

100-110: Host computer, 150-160: External storage device, 200-210: Volume, 300-310: Monitoring program, 400-410: External storage device management program, 500: ESC
ON I / F, 510-520 ... SCSI I / F or Fiber Channel
I / F, 600… LAN I / F.

Claims (1)

[Claims] 1. An active standby system using a computer and an external storage device, when a failure occurs in the active system, automatically shifts to the standby system so that processing can be continued and the active system is restored. A system capable of automatically restoring the contents of the external storage device and automatically shifting processing to the active system.