On-line disk array reconfiguration

摘要

A system for performing on-line reconfiguration of a disk array in which a source logical volume is reconfigured to a destination logical volume. Disk array configuration is invoked if a new physical drive is inserted, or a drive is removed. Reconfiguration can also be performed if the user desires to change the configuration of a particular logical volume, such as its stripe size. The disk array reconfiguration is run as a background task by firmware on a disk controller board. The reconfigure task first moves data from the source logical volume to a posting memory such as RAM memory. The reconfigure task operates one stripe at a time, with the stripe size being that of the destination logical volume. Once a stripe of data is moved into the posting memory, it is written back to corresponding locations in the destination logical volume. The reconfigure task continues until all data in the source logical volume have been moved into the destination logical volume. While the reconfigure task is working on a particular logical volume, data remains accessible to host write and read requests.