Cisco Systems OL-26646-01 manual Mixing Drive Types in RAID Groups, Yes

Appendix C RAID Controller Considerations

Mixing Drive Types in RAID Groups

Table C-2lists the RAID options for the large form factor (LFF) version of the server.

Table C-2	Cisco UCS C22 Large Form Factor RAID Options
			Maximum	SCPM1	RAID Levels
Controller		Style	Drives		Supported	Required Cables
Embedded		Onboard	4 SATA	No	0, 1, 54, 10	4 drives: 1 mini-SAS
MegaRAID2			(default) or			UCSC-CABLE-A9
			4 SAS3
			internal
LSI MegaRAID		PCIe	4 internal	No	0, 1, 10	4 drives: 1 mini-SAS
9220-4i						UCSC-CABLE-A10
LSI MegaRAID SAS		PCIe	4 internal	No	0, 1, 5, 10, 50	4 drives: 1 mini-SAS
9240-8i						UCSC-CABLE-A10
LSI MegaRAID SAS		PCIe	4 internal	SCPM	0, 1, 5, 6, 10, 50, 60	4 drives: 1 mini-SAS
9265CV-8i						UCSC-CABLE-A10

1.SCPM = SuperCap power module (the RAID backup unit).

2.The embedded RAID controller must be enabled in the BIOS.

3.Support for four SAS drives requires an optional SCU upgrade ROM module on the motherboard.

4.Embedded RAID 5 support requires an optional software key module.

Mixing Drive Types in RAID Groups

Table C-3lists the technical capabilities for mixing hard disk drive (HDD) and solid state drive (SSD) types in a RAID group. However, see the best practices recommendations that follow for the best performance.

Table C-3 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

Best Practices For Mixing Drive Types in RAID Groups

For the best performance, follow these guidelines:

•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.

Cisco UCS C22 Server Installation and Service Guide

OL-26646-01 C-3