Chapter 2. Primary CLI Syntax Reference
64
3ware 9000 Series Serial ATA Controller CLI Guide
group=3|4|5|6
indicates the number of disks per group for a RAID 50 type.
(This attribute can only be used when type=raid50.) Recall that a RAID 50 is
a multi-tier array. At the bottom-most layer, N number of disks per group are
used to form the RAID 5 layer. These RAID 5 arrays are then integrated into a
RAID 0. This attribute allows you to specify the number of disks in the RAID
5 level. Valid values are 3, 4, 5 and 6. For example
group=3
indicates 3 disks
of RAID 5 at the bottom layer of RAID 50.
Note that a sufficient number of disks are required for a given pattern or disk
group. For example, given 6 disks, specifying 3 will create two RAID 5
arrays. With 12 disks, specifying 3 will create four RAID 5 arrays under the
RAID 0 level. With only 6 disks a grouping of 6 is not allowed, as you would
basically be creating a RAID 5.
The default RAID 50 grouping varies, based on number of disks. For 6 and 9
disks, default grouping is 3. For 8 disks, the default grouping is 4. For 10
disks, the default grouping is 5, and for 12 disks, the default grouping is 4. In
the case of 12, the disks could be grouped into groups of 3, 4, or 6 drives. A
grouping of 4 is set by default as it provides the best of net capacity and
performance.
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
Table 12: Supported Stripe Sizes
Model
R0
R1
R5
R10
JBOD
Spare
R50
Single
9K
16
N/A
16
16
N/A
N/A
16
N/A
64
64
64
64
256
256
256
256
Table 13: Supported Stripe Sizes
Model
R0
R1
R5
R10
JBOD
Spare
R50
Single
9K
16
N/A
16
16
N/A
N/A
16
N/A
64
64
64
64
256
256
256
256
