Mixing Drive Types In Raid Groups; Raid Backup Units - Cisco UCS C220 M4 Installation And Service Manual

Mixing Drive Types in RAID Groups

Mixing Drive Types in RAID Groups

Table C-2
types in a RAID group. However, see the recommendations that follow for the best performance.
Table C-2
Mix of Drive Types
in RAID Group
SAS HDD + SATA HDD
SAS SSD + SATA SSD
HDD + SSD
Mixing Drive Types in RAID Groups
For the best performance, follow these guidelines:
•
•
•

RAID Backup Units

This server supports installation of one supercap Power Module (SCPM). The unit mounts to a bracket
in-line with the fan modules (see
The optional SCPM provides approximately three years of backup for the disk write-back cache DRAM
in the case of a sudden power loss by offloading the cache to the NAND flash.
For SCPM replacement instructions, see
page
Cisco UCS C220 M4 Server Installation and Service Guide
C-6
lists the technical capabilities for mixing hard disk drive (HDD) and solid state drive (SSD)
Drive Type Mixing in RAID Groups
Use either all SAS or all SATA drives in a RAID group.
Use the same capacity for each drive in the RAID group.
Never mix HDDs and SSDs in the same RAID group.
3-33.
Allowed?
Yes
Yes
No
Figure 3-20).
Replacing the Supercap Power Module (RAID Backup),
Appendix C RAID Controller Considerations
OL-32473-01