Cisco Systems UCSRAID9266CV, C220, 9266CV-8i RAID Backup Units, Mixing Drive Types in RAID Groups

Appendix C RAID Controller Considerations

Mixing Drive Types in RAID Groups

Mixing Drive Types in RAID Groups

Following are the rules for mixing hard disk drive (HDD) and solid state drive (SSD) types in a RAID group.

Table C-5 Drive Type Mixing in RAID Groups

Mix of Drive Types
in RAID Group	Allowed?
SAS HDD + SATA HDD	Yes
SAS SSD + SATA SSD	Yes
HDD + SSD	No

RAID Backup Units

This server supports installation of one RAID battery backup unit (BBU) or one SuperCap Power Module (SCPM). The unit mounts to a holder on the left-side air baffle (see Figure 3-24).

•The optional LSI BBU is available only when using the LSI MegaRAID controller cards. This BBU provides approximately 72 hours of battery backup for the disk write-back cache DRAM in the case of sudden power loss.

•The optional SCPM is available only when using the LSI MegaRAID-CV controller cards. This supercap module provides approximately 3 years of backup for the disk write-back cache DRAM in the case of sudden power loss by offloading the cache to the NAND flash.

Cisco UCS C220 Server Installation and Service Guide

OL-25760-01 C-5