AMCC 9500S Computer Accessories User Manual


 
Chapter 2. CLI Syntax Reference
74 3ware Serial ATA RAID Controller CLI Guide
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).
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..
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
9000
a
a. Models 9500S, 9550SX, and 9590SE
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