Reference Guide

Mandatory Options
and Arguments
Optional Parameters Valid Parameters
Arguments
Description
block-level striping with two parity blocks
distributed across all member disks. RAID
6 provides protection against double disk
failures and failures while a single disk is
rebuilding. In case there is only one array,
RAID 6 may be a better option than a hot
spare disk.
• 10 — RAID 10 is a stripe of mirrors.
Multiple RAID 1 mirrors are created, and a
RAID 0 stripe is created over these.
• 50 — RAID 50 is a dual-level array that
uses multiple RAID 5 sets in a single array.
A single hard drive failure can occur in
each of the RAID 5 without any loss of
data on the entire array. Although the
RAID 50 has increased write performance,
when a hard drive fails and reconstruction
takes place, performance decreases,
data/program access is slower, and
transfer speeds on the array are affected.
• 60 — RAID 60 is a combination of RAID 6
and RAID 0. A RAID 0 array is striped
across RAID 6 elements. It requires at
least 8 disks.
-ctrl -ac=cvd -
c=id -ad=
ch:targ,ch:tar
g, ... [or
ch:targ:encl,.
..]
or
controller
action=
createvdisk
controllerid=
id adisk=
channel:target
: lun,
channel:target
: lun,...
[or
channel:target
:
enclosure,...]
-rp or
readpolicy
ra, ara, nra, rc, nrc
CAUTION: If the controller is changed
from SCSI to RAID mode, expect data
loss to occur. Back up any data you want
to save before changing the modes.
Sets the SCSI read policy for the virtual disk.
Specify the SCSI read policy for the logical
drive. The valid arguments are:
• ra — (read-ahead) The controller reads
sequential sectors of the disk when
seeking data.
• ara — (Adaptive Read-Ahead) The
controller initiates read-ahead only if the
two most recent read requests accessed
sequential sectors of the disk. If
subsequent read requests access random
sectors of the disk, the controller reverts
to No-Read-Ahead policy. The controller
continues to evaluate whether or not read
requests are accessing sequential sectors
of the disk and can initiate read-ahead if
necessary.
• nra — (No-Read-Ahead) The controller
does not read sequential sectors of the
disk when seeking data.
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