Dell Storage Manager 2020 R1 Administrator's Guide

Distributed Sparing

When updating to Storage Center version 7.3, a banner message prompts you to optimize disks. Clicking the link guides you through the process of optimizing disks for Distributed Sparing. During disk optimization, a meter displays the progress in the Disks view. When disks are optimized, spare disk space is distributed across all drives in a drive folder and is designated as Spare Space. This allows the system to use all disks in a balanced and optimized manner, and ensures the fastest recovery time following a disk failure. Distributed Sparing is the default for systems shipping with Storage Center version 7.3 or later.

Reserved Spare Drive

Prior to Storage Center version 7.3, a spare drive is used as a replacement for the failed drive. Storage Center designates at least one drive spare for each disk class. Storage Center groups drives into groups of no more than 21 drives, with one drive in each group designated as a spare drive. For example, a disk class containing 21 drives will have 20 managed drives and one spare drive. A disk class with 22 drives will have 20 managed drives and two spare drives. Storage Center designates the one additional drive as a spare drive. Storage Center designates the largest drives in the disk class as spare drives.

When Storage Center consumes a spare drive, a feature called Drive Spare Rightsizing allows Storage Center to modify the size of a larger capacity spare drive to match the capacity of the drive being replaced in the tier. After modifying the size of the drive in this manner, it cannot be modified to its original size. Drive Spare Rightsizing is enabled by default for all controllers running Storage Center version 7.2 beginning with version 7.2.11. It allows Technical Support to dispatch larger capacity drives of the same disk class when the same size drive is not available, providing faster delivery times.