Dell EMC PowerVault MD 34XX/38XX Series Storage Arrays Administrator's Guide

Disk pooling allows you to distribute data from each virtual disk randomly across a set of physical disks. Disk pooling provides RAID protection and consistent performance across a set of physical disks logically grouped together in the storage array. Although there is no limit on the maximum number of physical disks that can comprise a disk pool, each disk pool must have a minimum of 11 physical disks. Additionally, the disk pool cannot contain more physical disks than the maximum limit for each storage array. The physical disks in each disk pool must:

• be SAS or nearline SAS
• have the same physical disk speed (RPM)
  NOTE: The maximum physical disk speed is 15,000 rpm for standard SAS and 7,200 rpm for 3.5" nearline SAS.
  NOTE: In a disk pool, the physical disks must have the same capacities. If the physical disks have different capacities, the MD Storage Manager uses the smallest capacity among the physical disks in the pool. For example, if your disk pool is comprised of several 4 GB physical disks and several 8 GB physical disks, only 4 GB on each physical disk is used.