HIGH-SPEED CHANGEOVER SYSTEM FOR INTER-SYSTEM SHARED DISK IN HOT STANDBY SYSTEM

摘要

PROBLEM TO BE SOLVED: To make a standby system quickly start a job without taking the consistency of data required in a file system or the like when a fault is generated in an active system and the job is to be switched to the standby system in the hot standby system. SOLUTION: Two disks accessible from both of the active system and the standby system are used, and normally for the two disks, one (disk 1) is updated only from the active system and the other disk (disk 2) is updated only from the standby system. The two disks are logically used as one disk, and in the case of updating the data, updating is performed by the disk controller of the active system for the disk 1. For the disk 2, a request is issued so as to update the data to the standby system by using a communication route between the active system and the standby system, and in the standby system, the data of the disk 2 are updated by using a standby system disk controller only in the case that updating is requested from the active system. In the case that the fault is generated in the active system and the job is to be switched to the standby system, the standby system quickly starts the job by using the data of the disk 2 without the need of taking the consistency of the file system.