RAID RANDOM DISTRIBUTION SCHEME

摘要

There is provided a computerized method, computerized system, a non-transitory program storage device and a computer program product for enabling allocation of segments in a RAID stripe to respective storage devices in a corresponding RAID group. A randomized distribution scheme is generated for randomly distributing the data segments and syndrome segments in a RAID stripe to respective storage devices in the RAID group. The randomized distribution scheme is used for distributing the segments in the at least one RAID stripe to the storage devices in the RAID group, such that any two failed storage devices in the RAID group would have the same first probability (P) for being protected by the same type-1 syndrome segment and the same second probability (1-P) for each one of the two failed storage devices being protected by a different type-1 syndrome segment, irrespective of the relative location of the two failed storage devices.

主权项

1. A computerized method of allocating segments in a RAID stripe to respective storage devices in a corresponding RAID group; each RAID stripe comprises a group of data segments arranged in a first subset of data segments and a second subset of data segments; the first subset is protected by a first type-1 syndrome segment, the second subset is protected by a second type-1 syndrome segment and the entire group of data segments is protected by a type-2 syndrome segment; the method comprising using a processor for:
generating a randomized distribution scheme for randomly distributing the data segments and syndrome segments in a RAID stripe to respective storage devices in the RAID group; and, responsive to a need to write data to the RAID group: generating at least one RAID stripe; and using the randomized distribution scheme for distributing the segments in the at least one RAID stripe to the storage devices in the RAID group, such that any two failed storage devices in the RAID group would have the same first probability (P) for being protected by the same type-1 syndrome segment and the same second probability (1-P) for each one of the two failed storage devices being protected by a different type-1 syndrome segment, irrespective of the relative location of the two failed storage devices.