Deployment Guide

Mandatory Options
and Arguments
Optional Parameters Valid Parameters
Arguments
Description
The valid arguments are:
• 0 — RAID 0 uses data striping, which is writing
data in equal-sized segments across the array
disks. RAID 0 does not provide data
redundancy.
• 1 — RAID 1 is the simplest form of maintaining
redundant data. In RAID 1, data is mirrored or
duplicated on one or more drives.
• 5 — RAID 5 provides data redundancy by using
data striping in combination with parity
information. Rather than dedicating a drive to
parity, the parity information is striped across all
disks in the array.
• 6 — RAID 6 is an extension of RAID 5 and uses
extra parity block. It uses 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. If 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 RAID 1 mirrors.
• 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 aected.
• 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:targ,
... [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 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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