Patent ID: 9658803
Date: 2017-05-23
CPC Classifications: G06F

Claim:
1. A method for use in managing accesses to storage, the method comprising: determining an amount of data storage space in use by a mapped logical volume, wherein storage is assigned to the mapped logical volume in slices that come from at least one redundant array of independent disks (RAID) group; determining RAID group characteristics of a RAID group in a storage pool used by the mapped logical volume; based on the amount of data storage space in use by a mapped logical volume and the RAID group characteristics, determining a number of physical data drives that provide backing storage for the mapped logical volume; and based on the determined number of physical data drives that provide backing storage for the mapped logical volume, controlling accesses to the mapped logical volume, wherein a number of accesses to the mapped logical volume is based on the number of physical data drives that provide backing storage for the mapped logical volume; wherein determining the number of physical data drives that provide backing storage for the mapped logical volume comprises: determining a first value based on a total number of physical data drives in the storage pool, wherein the storage pool comprises a first number of physical data drives in total and the first value equates to the first number; determining a second value by multiplying mapped logical volume size in slices and a number of physical data drives in a particular RAID group in the storage pool, wherein the particular RAID group comprises a smallest number of physical data drives of any RAID group in the storage pool; determining the smaller of the first and second values; comparing the smaller of the first and second values to a threshold, wherein the threshold is less than the first number of physical data drives in the storage pool; and based on the comparison, determining the number of physical data drives that provide backing storage for the mapped logical volume; wherein the threshold is determined to be the number of physical data drives that provide backing storage for the mapped logical volume when the smaller of the first and second values is greater than the threshold; and wherein the smaller of the first and second values is determined to be the number of physical data drives that provide backing storage for the mapped logical volume when the smaller of the first and second values is less than the threshold; and wherein a storage system includes a fairness process for assisting in reducing the possibility of a host overwhelming the storage system with requests to the mapped logical volume by limiting the number of accesses to the mapped logical volume based on the number of physical data drives that provide backing storage for the mapped logical volume.