Assignment of newly added data storage drives to an original data storage drive partnership group and a new data storage drive partnership group in a mapped RAID (redundant array of independent disks) system

A data storage system that provides RAID (Redundant Array of Independent Disks) data protection for a storage object, comprising:

• at least one storage processor including processing circuitry and a memory;
• an array of data storage drives communicably coupled to the storage processor, wherein the array of data storage drives includes an original partnership group of 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:
• generate a RAID mapping table, wherein the RAID mapping table contains a plurality of RAID extents, wherein each RAID extent contained in the RAID mapping table indicates a predetermined total number of drive extents that each persistently store host data written to the storage object, and wherein each drive extent comprises a contiguous region of non-volatile data storage located on one of the data storage drives, wherein the RAID mapping table contains an original RAID extent group corresponding to the original partnership group, wherein the original RAID extent group contains a plurality of RAID extents, and wherein all RAID extents contained in the original RAID extent group only indicate drive extents that are located on data storage drives that are contained in the original partnership group,
• detect the addition of a set of new data storage drives to the array of data storage drives,
• determine a total number of highest capacity data storage drives in the original partnership group,
• compare the total number of highest capacity data storage drives in the original partnership group to a minimum number of data storage drives required to provide RAID data protection for the storage object, and
• in response to the total number of highest capacity data storage drives in the original partnership group being at least as large as the minimum number of data storage drives required to provide RAID data protection for the storage object,
• i) add data storage drives from the set of new data storage drives in ascending order of capacity to the original partnership group until a total number of data storage drives in the original partnership group is equal to a maximum partnership group size,
• ii) create a new partnership group made up of those data storage drives in the set of new data storage drives that were not added to the original partnership group, and
• iii) create a new RAID extent group in the RAID mapping table, the new RAID extent group corresponding to the new partnership group, wherein the new RAID extent group contains a plurality of RAID extents, and wherein all RAID extents contained in the new RAID extent group only indicate drive extents that are located on data storage drives that are contained in the new partnership group.

A non-transitory computer readable medium for providing RAID (Redundant Array of Independent Disks) data protection for a storage object in a data storage system, wherein the data storage system includes a storage processor and an array of data storage drives communicably coupled to the storage processor, wherein the array of data storage drives includes an original partnership group of data storage drives, the non-transitory computer readable medium comprising instructions stored thereon that when executed on processing circuitry in the storage processor perform the steps of:

• generating a RAID mapping table, wherein the RAID mapping table contains a plurality of RAID extents, wherein each RAID extent contained in the RAID mapping table indicates a predetermined total number of drive extents that each persistently store host data written to the storage object, and wherein each drive extent comprises a contiguous region of non-volatile data storage located on one of the data storage drives, wherein the RAID mapping table contains an original RAID extent group corresponding to the original partnership group, wherein the original RAID extent group contains a plurality of RAID extents, and wherein all RAID extents contained in the original RAID extent group only indicate drive extents that are located on data storage drives that are contained in the original partnership group;
• detecting the addition of a set of new data storage drives to the array of data storage drives;
• determining a total number of highest capacity data storage drives in the original partnership group;
• comparing the total number of highest capacity data storage drives in the original partnership group to a minimum number of data storage drives required to provide RAID data protection for the storage object;
• and
• in response to the total number of highest capacity data storage drives in the original partnership group being at least as large as the minimum number of data storage drives required to provide RAID data protection for the storage object,
• i) adding data storage drives from the set of new data storage drives in ascending order of capacity to the original partnership group until a total number of data storage drives in the original partnership group is equal to a maximum partnership group size,
• ii) creating a new partnership group made up of those data storage drives in the set of new data storage drives that were not added to the original partnership group, and
• iii) creating a new RAID extent group in the RAID mapping table, the new RAID extent group corresponding to the new partnership group, wherein the new RAID extent group contains a plurality of RAID extents, and wherein all RAID extents contained in the new RAID extent group only indicate drive extents that are located on data storage drives that are contained in the new partnership group.