Description
This command defines the properties for a virtual
disk. You can use most parameters to define properties for one or
more virtual disks. You also can use some parameters to define properties
for only one virtual disk. The syntax definitions are separated to
show which parameters apply to several virtual disks and which apply
to only one virtual disk. Also, the syntax for virtual disk mapping
is listed separately.
-
NOTE: In configurations where
disk groups consist of more than 32 virtual disks, the operation can
result in host I/O errors or internal RAID controller module reboots
due to the expiration of the timeout period before the operation completes.
If you experience host I/O errors or internal RAID controller module
reboots, bring the host to a quiescent state and try the operation
again.
Syntax
set (allVirtualDisks | virtualDisk ["virtualDiskName"] | virtualDisks ["virtualDiskName1" ... "virtualDiskNameN"] |
virtualDisk <wwID>) (addCapacity = capacityValue(KB|MB|GB|TB|Bytes) | [addPhysicalDisks = (physicalDisk-spec-list)] |
cacheFlushModifier=cacheFlushModifierValue | cacheReadPrefetch = (TRUE | FALSE) | cacheWithoutBatteryEnabled=(TRUE | FALSE)
|
mediaScanEnabled=(TRUE | FALSE) | replicationCacheEnabled=(TRUE | FALSE) |
modificationPriority=(highest | high | medium | low | lowest) |
owner=(0 | 1) | preReadConsistencyCheck = (TRUE | FALSE) |
readCacheEnabled=(TRUE | FALSE) | consistencyCheckEnabled = (TRUE | FALSE) |
segmentSize = segmentSizeValueuserLabel = userlabelValuewriteCacheEnabled=(TRUE | FALSE) |
dataAssuranceDisabled=(TRUE | FALSE) | flashCacheEnabled=(TRUE | FALSE))
Parameters
Parameter |
Description |
allVirtualDisks
|
The properties for all virtual disks in the storage
array.
|
virtualDisk or
virtualDisks
|
The name of the specific virtual disk for which
you want to define properties. (You can enter more than one virtual
disk name if you use the
virtualDisks parameter.) Enclose
the virtual disk name in double quotation marks (" ") inside of square
brackets ([ ]).
|
virtualDisk
|
The World Wide Identifier (WWID) of the virtual
disk for which you are setting properties. You can use the WWID instead
of the virtual disk name to identify the virtual disk. Enclose the
WWID in angle brackets (< >).
-
NOTE: When running this command,
do not use colon separators in the WWID.
|
addCapacity
|
The setting to increase the storage size (capacity)
of the virtual disk for which you are defining properties. Size is
defined in units of bytes, KB, MB, GB, or TB. The default value is
bytes. This parameter is not valid for thin virtual disks.
-
NOTE: The maximum capacity
is 250 GB.
|
addPhysicalDisks
|
The setting to add new physical disks to the virtual
disk. For dense expansion enclosures, specify the enclosure ID value,
the drawer ID value, and the slot ID value for the physical disk.
For non-dense expansion enclosures, specify the enclosure ID value
and the slot ID value for the physical disk. Enclosure ID values are
0 to
99. Drawer ID values are
1 to
5. Slot ID values are
0 to
31. Enclose the enclosure ID value, drawer ID value, and
the slot ID value in parentheses. Use this parameter with the
addCapacity parameter if you need to specify additional physical
disks to accommodate the new size. This parameter is not valid for
disk pool virtual disks or for thin virtual disks.
Each
disk pool must be created from a minimum of 11 physical disks specified.
There is no upward limit of physical disks supported in a single disk
pool, but the number cannot exceed the number of physical disks supported
on the storage array.
|
cacheFlushModifier
|
The maximum amount of time that data for the virtual
disk stays in cache before the data is flushed to physical storage.
Valid values are listed in the Notes section.
|
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.
|
cacheWithoutBatteryEnabled
|
The setting to turn on or turn off caching without
batteries. To turn on caching without batteries, set this parameter
to
TRUE. To turn off caching without batteries, set
this parameter to
FALSE.
|
mediaScanEnabled
|
The setting to turn on or turn off media scan
for the virtual disk. To turn on media scan, set this parameter to
TRUE. To turn off media scan, set this parameter to
FALSE. (If media scan is disabled at the storage array level,
this parameter has no effect.)
|
replicationCacheEnabled
|
The setting to turn on or turn off the replication
cache. To turn on the replication cache, set this parameter to
TRUE. To turn off the replication cache, set this parameter
to
FALSE.
|
modificationPriority
|
The priority for virtual disk modifications while
the storage array is operational. Valid values are
highest,
high,
medium,
low,
or
lowest.
|
preReadConsistencyCheck
|
The setting to turn on or turn off preread consistency
checking. Turning on preread consistency checking verifies the consistency
of RAID redundancy data for the stripes containing the read data.
Preread consistency checking is performed on read operations only.
To turn on preread consistency checking, set this parameter to
TRUE. To turn off preread consistency checking, set this
parameter to
FALSE.
-
NOTE: Do not use this parameter
on non redundant virtual disks, such as RAID 0 virtual disks.
|
readCacheEnabled
|
The setting to turn on or turn off the read cache.
To turn on the read cache, set this parameter to
TRUE. To turn off the read cache, set this parameter to
FALSE.
|
consistencyCheckEnabled
|
The setting to turn on or turn off the write cache.
To turn on the write cache, set this parameter to
TRUE. To turn off the write cache, set this parameter to
FALSE.
|
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
|
userLabel
|
The new name that you want to give an existing
virtual disk. Enclose the new virtual disk name in double quotation
marks (" ").
|
writeCacheEnabled
|
The setting to turn on write cache capability. |
dataAssuranceDisabled
|
The setting to turn off data assurance for a specific
disk. For this parameter to have meaning, your disk must be capable
of data assurance. This parameter changes a virtual disk from one
that supports data assurance to a disk that cannot support data assurance.
-
NOTE: This option is only valid for enablement, if the disks support DA.
To remove data assurance from a disk that supports data assurance,
set this parameter to TRUE.
-
NOTE: If you remove data assurance from
a disk, you cannot reset data assurance for that disk.
To reset data assurance for the data on a disk, from which you removed
data assurance, perform these steps:
- Remove the data from the disk.
- Delete the disk.
- Recreate a new disk with the properties of the deleted disk.
- Set data assurance for the new disk.
- Move the data to the new disk.
|
Notes
When you use this command, you can specify one or
more of the optional parameters.
You can apply
these parameters to only one virtual disk at a time:
-
addCapacity
-
segmentSize
-
userLabel
Add
Capacity, Add Physical Disks, And Segment Size
Setting the
addCapacity parameter, the
addPhysicalDisks parameter, or the
segmentSize parameter starts a
long-running operation that you cannot stop. These long-running operations
are performed in the background and do not prevent you from running
other commands. To show the progress of long-running operations, use
the
show virtualDisk actionProgress command.
Cache Flush Modifier
Valid values for the cache flush modifier are listed
in the following table.
Value |
Description |
Immediate
|
Data is flushed as soon as it is placed into the
cache.
|
250
|
Data is flushed after 250 ms. |
500
|
Data is flushed after 500 ms. |
750
|
Data is flushed after 750 ms. |
1
|
Data is flushed after 1 s. |
1500
|
Data is flushed after 1500 ms. |
2
|
Data is flushed after 2 s. |
5
|
Data is flushed after 5 s. |
10
|
Data is flushed after 10 s. |
20
|
Data is flushed after 20 s. |
60
|
Data is flushed after 60 s (1 min.). |
120
|
Data is flushed after 120 s (2 min.). |
300
|
Data is flushed after 300 s (5 min.). |
1200
|
Data is flushed after 1200 s (20 min.). |
3600
|
Data is flushed after 3600 s (1 hr). |
Infinite
|
Data in cache is not subject to any age or time
constraints. The data is flushed based on other criteria that are
managed by the RAID controller module.
|
Cache
Without Battery Enabled
Write caching without
batteries enables write caching to continue if the RAID controller
module batteries are completely discharged, not fully charged, or
not present. If you set this parameter to
TRUE without
an uninterruptible power supply (UPS) or other backup power source,
you can lose data if the power to the storage array fails. This parameter
has no effect if write caching is disabled.
Modification Priority
Modification priority defines the amount of system
resources that are used when modifying virtual disk properties. If
you select the highest priority level, the virtual disk modification
uses the most system resources, which decreases the performance for
host data transfers.
Cache Read Prefetch
The
cacheReadPrefetch parameter enables
the RAID controller module to 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 disk 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.
Segment Size
The size of a segment determines how many data blocks
that the RAID controller module writes on a single physical disk in
a virtual disk before writing data on the next physical disk. Each
data block stores 512 bytes of data. A data block is the smallest
unit of storage. The size of a segment determines how many data blocks
that it contains. For example, an 8 KB segment holds 16 data blocks.
A 64 KB segment holds 128 data blocks.
When you
enter a value for the segment size, the value is checked against the
supported values that are provided by the RAID controller module at
run time. If the value that you entered is not valid, the RAID controller
module returns a list of valid values. Using a single physical disk
for a single request leaves other physical disks available to simultaneously
service other requests.
If the virtual disk is in
an environment where a single user is transferring large units of
data (such as multimedia), performance is maximized when a single
data transfer request is serviced with a single data stripe. (A data
stripe is the segment size that is multiplied by the number of physical
disks in the disk group that are used for data transfers.) In this
case, multiple physical disks are used for the same request, but each
physical disk is accessed only once.
For optimal
performance in a multiuser database or file system storage environment,
set your segment size to minimize the number of physical disks that
are required to satisfy a data transfer request.