AMCC 9550SX, 9500S, 9590SE, 9650SE manual Supported Stripe Sizes

Chapter 2. CLI Syntax Reference

the best of net capacity and performance). For 15 disks, the disks can be grouped into groups of 3 or 5 drives. For 16 disks, the disks can be grouped into groups of 4 or 8 drives.

Note that RAID-10 always has group=2, so an attribute specifying it’s group is not necessary.

stripe=Stripe consists of the stripe size to be used. The following table illustrates the supported and applicable stripes on unit types and controller models. Stripe size units are in KB (kilobytes).

Table 12: Supported Stripe Sizes

Model	R0	R1	R5	R6	R10	JBOD	Spare	R50	Single
7/8000	64	N/A	64	N/S	64	N/A	N/A	N/S	N/S
	128				128
	256				256
	512				512
	1024				1024
9000a	16	N/A	16	N/S	16	N/A	N/A	16	N/S
	64		64	N/S	64			64
	256		256	N/S	256			256
9650SE	16	N/A	16		16	N/A	N/A	16	N/S
	64		64	64	64			64
	256		256		256			256

a. Models 9500S, 9550SX, and 9590SE

noscan attribute instructs CLI not to notify the operating system of the creation of the new unit. By default CLI will inform the operating system. One application of this feature is to prevent the operating system from creating block special devices such as /dev/sdb and /dev/sdc as some implementations might create naming fragmentation and a moving target.

nocache attribute instructs CLI to disable the write cache on the migrated unit. Enabling write cache increases write performance at the cost of potential data loss in case of sudden power loss (unless a BBU or UPS is installed). By default the cache is enabled. To avoid the possibility of data loss in the event of a sudden power loss, it is recommended not to set nocache unless there is a BBU (battery backup unit) or UPS (uninterruptibleuninterruptible power supply) installed..

74 3ware Serial ATA RAID Controller CLI Guide