Computer system and storage system

摘要

A storage system is migrated without stopping service provision by a host computer. By this means, in a migration-source storage system, data of the cache memory is destaged, and, next, data received from the host computer is directly written in a logical unit by bypassing the cache memory. On the other hand, in a migration-destination storage system, communication with the migration-source storage system is performed to set setting information of a logical unit of the migration object into a logical unit management table and set a writing mode for the cache memory to a cache-bypass mode. After that, the migration-source storage system blocks a path to the host computer. The migration-destination storage system receives a report of the path block from the migration-source storage system and then opens a path between the own system and the host computer.

主权项

1. A computer system comprising:
a host computer; a first storage system having a first cache memory and a first logical unit; and a second storage system having a second cache memory and a second logical unit, wherein, when a connection destination of the host computer is migrated from the first storage system to the second storage system:
the first storage system is configured to apply a standby state to a writing of data for the first cache memory, destage data existing in the first cache memory to the first logical unit and then directly write data received via a first path from the host computer, in the first logical unit by bypassing the first cache memory such that the data is written via the first path in a cache-bypass mode immediately before storage migration;the second storage system is configured to communicate with the first storage system, automatically set setting information of the first logical unit of a migration object into a management table of the second logical unit by designating the migration object, and set a writing mode for the second cache memory to the cache-bypass mode;the first storage system is configured to logically block the first path after the writing mode is set to the cache-bypass mode in the second storage system; andthe second storage system, having received a report of a block of the first path, is configured to logically open a second path set in advance with the host computer and to be physically connected with the host computer, and, when the second storage system receives data via the second path, the second storage system is configured to write the data in the first logical unit via the second cache memory immediately after the first path is blocked and the second path is opened.