Dell PowerVault ME5 Series Administrator's Guide

RAID selection

A pool is created by adding disk groups to it. Disk groups are based on RAID technology.

The following table describes the characteristics and use cases of each RAID level:

Table 1. RAID level characteristics and use cases
RAID level	Protection	Performance	Capacity utilization	Application use cases	Suggested disk speed
RAID 1/RAID 10	Protects against up to one disk failure per mirror set	Great random I/O performance	Poor: 50% fault tolerance capacity loss	Databases, OLTP, Exchange Server	10K, 7K
RAID 5	Protects against up to one disk failure per RAID set	Good sequential I/O performance, good random read I/O performance, moderate random write performance	Great: One-disk fault tolerance capacity loss	Big data, media and entertainment (ingest, broadcast, and past production)	10K, lower capacity 7K
RAID 6	Protects against up to two disk failures per RAID set	Good sequential I/O performance, good random read I/O performance, moderate random write performance (lower than RAID5)	Moderate: Two-disk fault tolerance capacity loss	Archive, parallel distributed file system	High capacity 7K
ADAPT	Distributed erasure coding with dual disk failure protection supports 16+2 or 8+2 stripe width	Very fast rebuilds, no spare disks (built-in spare capacity), large storage pools, simplified initial deployment and expansion	0% of capacity used for fault tolerance for8+2; 11.1% of capacity used for fault tolerance for 16+2	Provides flexible storage, well suited or most workloads other than those using very few disks, or requiring a high number of writes	High capacity 7K