Patent ID: 9690660
Date: 2017-06-27
CPC Classifications: G06F

Claim:
1. A method, performed by a data storage device, of recovering from a failure of a disk within a declustered RAID arrangement, the declustered RAID arrangement including N disks, each disk having a plurality of splits, the declustered RAID arrangement having a plurality of RAID groups, each RAID group distributed over a plurality less than N of members on distinct splits on distinct disks of the N disks, N being an integer greater than one, the method comprising: receiving an indication that the disk has failed, the failed disk storing a set of members of various RAID groups of the plurality of RAID groups; identifying, with reference to a set of hard rules, a set of spare splits eligible to store reconstructed versions of the set of members, each spare split being a split which is currently not a member of any RAID group, resulting in a set of eligible members of the set of members being identified as eligible sources for each respective spare split of the set of spare splits; searching for an assignment between each member of the set of members and a respective eligible spare split of the set of spare splits; and upon finding an assignment, reconstructing each member of the various RAID groups stored on the failed disk onto its respective assigned spare split; wherein searching for the assignment includes applying a set of weighted rules to generate a weighted score for each pair of one spare split and one of its respective eligible sources.