Dell PowerVault MD3060e Series, Руководство CLI, Страница: 107 / 226

Parameter Description
NOTE: A space must be added between the last digit and the size
(bytes, KB, MB, or GB) for values greater than 9. If you do not specify
a capacity, all the available physical disk capacity in the disk group is
used. If you do not specify the capacity unit, bytes is used as the
default unit.
owner The setting for which RAID controller module owns the disk group. Valid
RAID controller module identifier values are
0
and
1
. The identifier value is
0
for the RAID controller module on the top and
1
for the RAID controller
module on the bottom when viewed from the rear of the enclosure. If you
do not specify an owner, the RAID controller module firmware determines
the owner.
cacheReadPrefetch The setting to turn on or turn off cache read prefetch. To turn off cache
read prefetch, set this parameter to
FALSE
. To turn on cache read
prefetch, set this parameter to
TRUE
.
segmentSize The amount of data (in KB) that the RAID controller module writes on a
single physical disk in a virtual disk before writing data on the next
physical disk. Valid values are
8
,
16
,
32
,
64
,
128
,
256
, or
512
.
usageHint The setting for both the
cacheReadPrefetch
parameter and the
segmentSize
parameter to be default values. The default values are
based on the typical I/O usage pattern of the application that is using the
virtual disk. Valid values are
fileSystem
,
dataBase
, or
multiMedia
.
enclosureLossProtect The setting to enforce enclosure loss protection when you create the disk
group. To enforce enclosure loss protection, set this parameter to
TRUE
.
The default value is
FALSE
.
drawerLossProtect The setting to enforce drawer loss protection when you create the disk
group. To enforce drawer loss protection, set this parameter to
TRUE
. The
default value is
FALSE
.
securityType The setting to specify the security level when creating the disk groups and
all associated virtual disks.
•
none
—The disk group and virtual disks are not secure.
•
capable
—The disk group and virtual disks are capable of
having security set, but security has not been enabled.
•
enabled
—The disk group and virtual disks have security
enabled.
Additional Information
Cache Read Prefetch
The
cacheReadPrefetch
command lets the RAID controller module copy additional data blocks into cache while
the RAID controller module reads and copies data blocks that are requested by the host from the physical disks into
cache. This action increases the chance that a future request for data can be fulfilled from cache.
Cache read
prefetch
is important for multimedia applications that use sequential data transfers. The configuration settings for
the storage array that you use determine the number of additional data blocks that the RAID controller module reads into
cache. Valid values for the
cacheReadPrefetch parameter are
TRUE
or
FALSE
.
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