Patent ID: 7844776

Claim:
A disk array unit capacity expansion handling method for use by a computer platform that is equipped with a disk array unit having a cluster of disks for performing a capacity expansion procedure on the disk array unit when a new disk is added to the disk cluster, the disk array unit capacity expansion handling method comprising: duplicating each block of data stored in the original disk cluster by a predefined data length into a buffer memory area; rebuilding the data that are currently stored in the buffer memory area onto the newly-added disk under a prespecified disk array data storage mode; during runtime of the capacity expansion procedure, if the computer platform issues an access request to the disk array unit, responding by issuing an access address inspection enable message; responding to the access address inspection enable message by inspecting the relative location of the requested address of the access request in reference to current active expanding zone on the original disk cluster; if the requested address is within an already-expanded area, controlling an access operation on the newly-added disk to gain access to requested data; if the requested address is within an unexpanded area, controlling an access operation on the original disk cluster to gain access to requested data; and if the requested address is within the active expanding zone, inspecting the attribute of the access request; if the access request is a read request, controlling an access operation on the buffer memory area to gain access to requested data; otherwise, if the access request is a write request, returning a device busy message to the computer platform and inhibiting the access request until the rebuilding of the data in the current active expanding zone has completed, wherein if the requested address of the access request is before the address range of the active expanding zone, then the requested address is determined to have been rebuilt on the newly-added disk and the disk array unit is informed to read the newly-added disk during runtime of the capacity expansion procedure; whereas if the requested address is after the address range of the active expanding zone, then the requested address is determined to have not been rebuilt and the disk array unit is informed to read the original disk cluster during runtime of the capacity expansion procedure.