Chapter 3. Legacy CLI Syntax Reference
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3ware 9000 Series Serial ATA Controller CLI Guide
gdsk_grp
indicates the number of disks per group for a RAID 50 type. A
RAID 50 is a multi-tier array. At the most bottom 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 option allows you to specify the number of
disks in the RAID 5 level. Valid values are 3, 4, 5 and 6.
Note that a sufficient number of disks are required for a given pattern or disk
group. For example, given 6 disks, specifying 3 creates two RAID 5 arrays.
However given 12 disks, specifying 3 creates four RAID 5 arrays under the
RAID 0 level. Given 6 disks, specifying 6 is not allowed as you would
basically be creating a RAID 5.
The default RAID 50 grouping (
gdsk_grp)
varies based on number of disks.
For 6 and 9 disks, the 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, 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.
noscan
switch instructs CLI not to notify OS of the creation of the new unit.
By default CLI informs the OS. One application of this feature is to avoid OS
creating block special devices such as /dev/sdb, /dev/sdc as some
implementations might create naming fragmentation and creating a moving
target.
nocache
switch instructs CLI not to enable the write cache. Enabling write
cache increases performance at the cost of high-availability.
autoverify
switch enables the autoverify attribute on the unit that is to be
created. This feature is not supported on model 7000/8000. Autoverify is used
in conjunction with the scheduling option. If autoverify is enabled, the array is
verified repeatedly during a scheduled verify window. If autoverify is
disabled, verify is not initiated by the controller and must be started manually.
ignoreECC
switch enables the ignoreECC/OverwriteECC attribute on the
unit that is to be created. The following table illustrates the supported Model-
UnitType. This table only applies to setting this feature at Unit Creation time.
Generally ignoreECC applies to redundant units.
256
256
256
256
Table 16: Supported Model-Unit Types
Model
R-0
R-1
R-5
R-10
R-50
Single
JBOD
Spare
7K/8K
No
No
No
No
No
No
No
No
9K
No
Yes
Yes
Yes
No
No
Yes
No
Table 15: Supported Stripe Sizes
