Cisco Systems OL-26646-01 SuperCap Power Modules RAID Backup Units, RAID Controller Migration

Appendix C RAID Controller Considerations

SuperCap Power Modules (RAID Backup Units)

SuperCap Power Modules (RAID Backup Units)

This server supports installation of one SuperCap power module (SCPM). The backup unit mounts to a holder near the cooling fans (see Figure 3-23). The SCPM is available only when using the optional 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.

For SCPM replacement instructions, see Replacing the SuperCap Power Module (RAID Backup Unit), page 3-41.

RAID Controller Migration

This server supports hardware RAID (PCIe controller cards) and embedded software RAID. See Table C-4for which migrations are allowed and a summary of migration steps.

Table C-4	RAID Controller Migration
Starting RAID Controller		Migrate to HW RAID Allowed?			Migrate to SW RAID Allowed?
None (no drives)		Allowed			Allowed
Onboard SCU Storage		1.	Install card.		1.	Install desired upgrade
support is Disabled in BIOS		2.	Install cables.			modules to motherboard.
					2. Enable SCU storage support
						in BIOS.
					3.	Install cables.
Embedded SW RAID					Not applicable
Onboard SCU Storage
		Caution Data migration from
support is Enabled in BIOS				SW RAID to HW RAID
				is not supported and
				could result in data loss.
		Allowed only before there is data
		on the drives; data migration is not
		supported.
		1.	Disable SCU storage support
			in BIOS.
		2.	Install card.
		3.	Install cables.
HW RAID		Not applicable			Not allowed
Onboard SCU Storage
support is Disabled in BIOS

Cisco UCS C22 Server Installation and Service Guide

C-4 OL-26646-01