Adaptive rebuild scheduling scheme

摘要

Method and apparatus for redundant array of independent disks (RAID) recovery are disclosed. In one embodiment, a RAID controller schedules requests to rebuild failed drives based on the wear state of secondary drives and input/output (I/O) activity. The controller may be configured to assign higher scheduling priority to rebuild requests only when necessary, so as to reduce the time needed for the rebuild and to avoid affecting performance of the RAID system. In particular, the controller may give higher priority to rebuild requests if secondary drive failure is likely. In addition, the controller may determine when write-intensive periods occur, and assign lower priority to rebuild requests during such periods.

主权项

1. A method for data recovery in a storage system in which fault tolerance in the storage system is provided using multiple copies of data, comprising:
receiving a request to rebuild a failed drive in the storage system; determining states of one or more secondary drives associated with the rebuild request; if one or more of the secondary drives are in a failing state, prioritizing a rebuild operation over read and write operations; and if none of the secondary drives are in a failing state, delaying the rebuild operation if the storage system is in a write-intensive period.