Raid reliability with a provisional spare disk
AssigneeDell Products L.P.
InventorsKuolin Hua, Kunxiu Gao, Michael Scharland
Life of this patent
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Abstract
Disks of equal storage capacity in a disk cluster have M*W partitions, where RAID width W=D+P. RAID (D+P) protection groups are implemented on the disks with protection group members stored in individual partitions. An amount of storage capacity equal to the storage capacity of one disk is distributed across multiple disks in spare partitions. The spare partitions may be distributed such that no more than one spare partition resides on a single disk. M may be selected to optimize rebuild latency. The protection group members of a failed disk are rebuilt in the distributed spare partitions and subsequently relocated to a provisional spare drive. The populated provisional spare drive replaces the failed drive.
Claims20
An apparatus, comprising:
- a storage array comprising:
- at least one compute node comprising at least one processor and non-transitory computer-readable memory;
- a plurality of data storage disks that are accessed by the at least one compute node and used to store data that is accessed via the at least one compute node, each of the data storage disks being associated with one disk cluster that contains Redundant Array of Independent Disks (RAID) (D+P) protection groups where RAID width W=D+P and each disk has M*W indexed partitions of equal storage capacity and each member of ones of the RAID protection groups is located on one of the partitions on a different one of the plurality of data storage disks;
- a provisional spare disk that is present in the storage array prior to failure of one of the data storage disks of the disk cluster;
- and
- a disk manager configured to:
- distribute spare partitions across a plurality of the disk clusters;
- and
- responsive to detection of a failed one of the data storage disks:
- rebuild protection group members of the failed data storage disk on the distributed spare partitions such that each rebuilt member of ones of the RAID protection groups of the failed data storage disk is located on one of the partitions on a different one of the plurality of data storage disks;
- and
- relocate rebuilt protection group members from the distributed spare partitions to the provisional spare disk.
A method implemented by a storage array comprising at least one compute node comprising at least one processor and non-transitory computer-readable memory and a plurality of data storage disks that are accessed by the at least one compute node and used to store data that is accessed via the at least one compute node, each of the data storage disks being associated with one disk cluster that contains Redundant Array of Independent Disks (RAID) (D+P) protection groups where RAID width W=D+P and each disk has M*W indexed partitions of equal storage capacity and each member of ones of the RAID protection groups is located on one of the partitions on a different one of the plurality of data storage disks, the method comprising:
- distributing spare partitions across a plurality of the disk clusters;
- and
- responsive to detection of a failed one of the data storage disks:
- rebuilding protection group members of the failed data storage disk on the distributed spare partitions;
- and
- relocating rebuilt protection group members from the distributed spare partitions to the provisional spare disk, wherein the provisional spare disk is present in the storage array prior to detection of the failed one of the data storage disks.
A non-transitory computer-readable storage medium storing instructions that when executed by a storage array comprising at least one compute node comprising at least one processor and non-transitory computer-readable memory and a plurality of data storage disks that are accessed by the at least one compute node and used to store data that is accessed via the at least one compute node, each of the data storage disks being associated with one disk cluster that contains Redundant Array of Independent Disks (RAID) RAID (D+P) protection groups where RAID width W=D+P and each disk has M*W indexed partitions of equal storage capacity and each member of ones of the RAID protection groups is located on one of the partitions on a different one of the plurality of data storage disks, cause the storage array to perform a method for recovering from disk failure, the method comprising:
- distributing spare partitions across a plurality of the disk clusters;
- and
- responsive to detection of a failed one of the data storage disks:
- rebuilding protection group members of the failed data storage disk on the distributed spare partitions;
- and
- relocating rebuilt protection group members from the distributed spare partitions to the provisional spare disk, wherein the provisional spare disk is present in the storage array prior to detection of the failed one of the data storage disks.
Dependencies are inferred from the claim text.