Methods and apparatus for marking writes on a write-protected failed device to avoid reading stale data in a RAID storage system

摘要

Methods and apparatus for improved building of a hot spare storage device in a RAID storage system while avoiding reading of stale data from a failed storage device. In the recovery mode of the failed device, all data is write protected on the failed device. A RAID storage controller may copy as much readable data as possible from the failed device to the hot spare storage device. Unreadable data may be rebuilt using redundant information of the logical volume. Write requests directed to the failed device cause the addressed logical block address (LBA) to be marked as storing stale data. When a read request is directed to such a marked LBA, the read request returns an error status from the failed device to indicate that the data is stale. The RAID controller then rebuilds the now stale data for that LBA from redundant information of the logical volume.

主权项

1. A method operable within a storage device, the storage device adapted to couple with a Redundant Array of Independent Drives (RAID) storage controller, the method comprising:
detecting a failure of the storage device; automatically reconfiguring the storage device into a recovery mode of operation in response to sensing the failure; responsive to entering the recovery mode, performing the steps of: receiving a write request to store supplied data at a write logical block address (LBA); marking the write LBA as storing stale data in response to receipt of the write request; receiving a read request requesting return of identified data stored at a read LBA; determining whether the read LBA is marked as storing stale data responsive to receipt of the read request; completing the read request by returning the identified data stored at the read LBA in response to a determination that the read LBA is not storing stale data; and failing the read request in response to a determination that the read LBA is marked as storing stale data.