Priority based raid (redundant array of independent disks) rebuild for a data storage system

A data storage system comprising:

• processing circuitry and a memory;
• a plurality of non-volatile data storage drives;
• and
• wherein the memory has program code stored thereon, wherein the program code, when executed by the processing circuitry, causes the processing circuitry to:
• organize non-volatile data storage of a data storage system into a plurality of RAID extents, wherein each RAID extent comprises a plurality of logically contiguous RAID stripes;
• in response to detection of a failed drive in the data storage system, perform an initial rebuilding pass on each one of the RAID extents, wherein the initial rebuilding pass recovers data that was previously stored on the failed drive and was located within high priority RAID stripes in the RAID extent;
• and
• after the initial rebuilding pass is completed on all of the RAID extents, perform at least one subsequent rebuilding pass on each one of the RAID extents that recovers data that was previously stored on the failed drive and was located within RAID stripes in the RAID extent that are not high priority.

A computer program product including a non-transitory computer readable medium having instructions stored thereon, wherein the instructions, when executed on processing circuitry, cause the processing circuitry to perform steps including:

• organizing non-volatile data storage of a data storage system into a plurality of RAID extents, wherein each RAID extent comprises a plurality of logically contiguous RAID stripes;
• in response to detecting a failed drive in the data storage system, performing an initial rebuilding pass on each one of the RAID extents, wherein the initial rebuilding pass recovers data that was previously stored on the failed drive and was located within high priority RAID stripes in the RAID extent;
• and
• after the initial rebuilding pass is completed on all of the RAID extents, performing at least one subsequent rebuilding pass on each one of the RAID extents that recovers data that was previously stored on the failed drive and was located within RAID stripes in the RAID extent that are not high priority.