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

Patent metadata

Field	Value
Publication number	US-10592111-B1
Application number	US-201715662742-A
Country	US
Kind code	B1
Filing date	Jul 28, 2017
Priority date	Jul 28, 2017
Publication date	Mar 17, 2020
Grant date	Mar 17, 2020

Abstract

Technology within a mapped RAID (Redundant Array of Independent Disks) data storage system for avoiding wasted capacity in a hybrid array of data storage drives. Drives from a set of new drives may be added to an original partnership group of drives such that the number of highest capacity drives in the original partnership group remains or is made to be at least as large as a minimum number of drives required to provide RAID data protection. Drives may also be added to the original partnership group such that the number of highest capacity drives in a newly created partnership group is also at least as large as the minimum number of drives required to provide RAID data protection. The minimum required number of drives may be equal to or greater than the total number of drive extents indicated by each RAID extent in a RAID mapping table.

First claim

What is claimed is:

1. A method of 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 method comprising:
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.

2. The method of claim 1 , wherein the highest capacity data storage drives in the original partnership group and the highest capacity data storage drives in the set of new data storage drives each have the same capacity, and further comprising, in response to the total number of highest capacity data storage drives in the original partnership group being less than the minimum number of data storage drives required to provide RAID data protection for the storage object:
determining a total number of highest capacity data storage drives in the set of new data storage drives;
comparing a sum of the total number of highest capacity data storage drives in the original partnership group and the total number of highest capacity data storage drives in the set of new data storage drives to double the minimum number of data storage drives required to provide RAID data protection for the storage object;
determining whether a number of new data storage drives can be added to the original partnership group that is equal to a difference between the total number of highest capacity data storage drives in the original partnership group and the minimum number of data storage drives required to provide RAID data protection for the storage object without a total number of data storage drives in the original partnership group exceeding a maximum partnership group size; and
in response to the sum of the total number of highest capacity data storage drives in the original partnership group and the total number of highest capacity data storage drives in the set of new data storage drives being at least as large as double the minimum number of data storage drives required to provide RAID data protection for the storage object, and to a determination that a number of new data storage drives can be added to the original partnership group that is equal to the difference between the total number of highest capacity data storage drives in the original partnership group and the minimum number of data storage drives required to provide RAID data protection for the storage object without the total number of data storage drives in the original partnership group exceeding the maximum partnership group size,
i) adding highest capacity data storage drives from the set of new data storage drives to the original partnership group until the total number of highest capacity data storage drives in the original partnership group is equal to the minimum number of data storage drives required to provide RAID data protection for the storage object,
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.

3. The method of claim 1 , wherein the highest capacity data storage drives in the original partnership group and the highest capacity data storage drives in the set of new data storage drives each have the same capacity, and further comprising, in response to the total number of highest capacity data storage drives in the original partnership group being less than the minimum number of data storage drives required to provide RAID data protection for the storage object and to the sum of the total number of highest capacity data storage drives in the original partnership group and the total number of highest capacity data storage drives in the set of new data storage drives being less than double the minimum number of data storage drives required to provide RAID data protection for the storage object:
comparing the sum of the total number of highest capacity data storage drives in the original partnership group and the total number of highest capacity data storage drives in the set of new data storage drives to the minimum number of data storage drives required to provide RAID data protection for the storage object;
determining whether a number of new data storage drives can be added to the original partnership group that is equal to a difference between the total number of highest capacity data storage drives in the original partnership group and the minimum number of data storage drives required to provide RAID data protection for the storage object without a total number of data storage drives in the original partnership group exceeding a maximum partnership group size; and
in response to the sum of the total number of highest capacity data storage drives in the original partnership group and the total number of highest capacity data storage drives in the set of new data storage drives being at least as large as the minimum number of data storage drives required to provide RAID data protection for the storage object, and to a determination that a number of new data storage drives can be added to the original partnership group that is equal to th

Assignees

• Emc Ip Holding Co Llc

Inventors

• Wang Sheng
• Dong Jibing
• Han Geng
• Xu Xinlei
• Gao Jian
• Ree Sun
• Wahl Michael

Classifications

• G06F3/0689

  Disk arrays, e.g. RAID, JBOD · CPC title

• G06F3/0631 Primary

  by allocating resources to storage systems · CPC title

• G06F3/0607 Primary

  by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device · CPC title

• G06F3/067

  Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS] · CPC title

• G06F3/0619

  in relation to data integrity, e.g. data losses, bit errors · CPC title