Deployment Guide

Table 314. Creating Virtual Disks (continued)
Mandatory Options
and Arguments
Optional Parameters Valid Parameters
Arguments
Description
channel:target:
lun,
channel:target:
lun,...
[or
channel:target:
enclosure,...]
● 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.
NOTE: The ra, ara, and nra options are
supported on the following RAID controllers
only:
● PERC 5/E Adapter, PERC 5/I Integrated,
PERC 5/i Adapter
● PERC 6/i Integrated, PERC 6/i Adapter,
PERC 6/E Adapter
● rc — (Read-Caching) Enables read
caching.
● nrc — (No-Read-Caching) Disables read
caching.
-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,...]
-sp or spanlength <number>
Creates a virtual disk comprised of the properties
supplied. The -sp option is optional and can be
added to the command line in any order after the
mandatory option combination.
NOTE: Spanlength is applicable only for RAID
50 and RAID 60. The minimum permissible
spanlength value for RAID 50 is 3 and for
RAID 60 is 4. The number of array disks
for creating a virtual disk should not be a
prime number and should be divisible by the
specified spanlength.
NOTE: For creating RAID 10, the PERC 9
firmware suggests the layout (number of
array disks) with uneven span (spans with
unequal number of array disks), though in a
span the number of disks remain even. For
example, for 32 disks, RAID 10 is created with
all the disks in one span and for 34 disks,
RAID 10 is created with 16 disks in one span
and 18 disks in the other span.
For SCSI controllers, the value of LUN should
always be 0.
For SAS controllers, the value of enclosure can be
non-zero, in which case you must specify values
for channel, target, and enclosure.
-ctrl -ac=cvd
-
c=id -ad=
ch:targ,ch:targ,
-ssz or
stripesize
<number>
Sets the stripe size for the virtual disk. The stripe
size is the amount of array disk space used on
170 RAIDCFG