Chapter 2. Primary CLI Syntax Reference
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3ware 9000 Series Serial ATA Controller CLI Guide
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
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 (uninterruptable power supply) installed..
autoverify
attribute enables the autoverify attribute on the unit that is to be
migrated. For more details on this feature, see “/cx/ux set autoverify=on|off”
on page 61.
Migration Process
In all cases of migration, the background migration process must be
completed before the newly sized unit is available for use. You can continue
using the original unit during this time. Once the migration is finished, a
reboot will be required if you are booted from the unit. For secondary storage,
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
