Apparatus and method of reducing physical storage systems needed for a volume group to remain active

摘要

A method, system and apparatus for reducing the number of physical storage systems needed for a volume group to remain active are provided. This is accomplished by creating mirroring sets out of the physical storage systems in the volume group and by setting up a policy that so long as one mirror out of each mirror set is available, the volume group should remain active. To activate a volume group (i.e., when the computer system is turned or reset), there have to be at least one full mirror set and at least one mirror out of each remaining mirror set available. These two policies guarantee that there will always be valid metadata in the system.