Patent ID: 9448735
Filing Date: 2016-09-20
CPC Classification: G06F

Claim Text:
1. A method for managing drive rebuild in a data storage system, the method comprising: providing a RAID group having multiple drives, wherein each drive in the RAID group is associated with a unique identifier; identifying a drive in the RAID group that has become inactive, wherein the RAID group is marked as being in a degraded state; activating a timer; maintaining a persistent bitmap, wherein the bitmap includes a plurality of bits and each bit indicates whether a corresponding portion of the identified drive has changed as a result of an I/O request issued while the drive is identified as inactive; if the inactive drive is subsequently identified as active before the timer expires, stopping the timer and initiating a rebuild procedure, wherein only portions of the identified drive corresponding to bits in the bitmap are rebuilt; clearing the bitmap and marking the RAID group as being in a healthy state; and else if the timer expires before the identified drive become active, initiating a full rebuild procedure.