Set Virtual Disk

??? Set Virtual Disk

Set Virtual Disk

This command defines the properties for a virtual disk. You can use most parameters to define properties for one or more virtual disks; however, you 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.

Syntax Applicable to One or More Virtual Disks

set (allVirtual Disks | virtualDisk ["virtualDiskName"] | virtual disks ["virtualDiskName1" ... "virtualDiskNamen"] | virtualDisk <wwn>) cacheFlushModifier=cacheFlushModifierValue cacheWithoutBatteryEnabled=(TRUE | FALSE) mediaScanEnabled=(TRUE | FALSE) mirrorCacheEnabled=(TRUE | FALSE) modificationPriority=(highest | high | medium | low | lowest) owner=(a | b) readCacheEnabled=(TRUE | FALSE) writeCacheEnabled=(TRUE | FALSE) cacheReadPrefetch=(TRUE | FALSE)

Syntax Applicable to Only One Virtual Disk

set (virtualDisk ["virtualDiskName"] | virtualDisk <wwn>) addCapacity=virtual diskCapacity [addPhysical Disks=(trayID1,slotID1 ... trayIDn,slotIDn)] consistencyCheckEnabled=(TRUE | FALSE) segmentSize=segmentSizeValue userLabel=virtualDiskName

Syntax Applicable to Virtual Disk Mapping

set (virtualDisk ["virtualDiskName"] | virtualDisk <wwn> | accessVirtualDisk) logicalUnitNumber=LUN (host="hostName" | hostGroup=("hostGroupName" | defaultGroup)

Parameters

Parameter Description

allVirtual Disks
Use this parameter to define the properties for all virtual disks in the storage array.

virtualDisk or virtual disks
This parameter specifies 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 virtual diskNames parameter). Enclose the virtual disk name in double quotation marks (??? ???) inside of square brackets ([ ]).

virtualDisk
This parameter specifies the World Wide Name (WWN) of the virtual disk for which you are setting properties. You can use the WWN instead of the virtual disk name to identify the virtual disk. Enclose the WWN in angle brackets (< >).

cacheFlushModifier
Maximum amount of time that data for the virtual disk remains in cache before being flushed to physical storage. Valid values are listed in the following "Notes" section.

cacheWithoutBatteryEnabled
Turns on or off caching without batteries. To turn caching without batteries on, set this parameter to TRUE. To turn caching without batteries off, set this parameter to FALSE.

mediaScanEnabled
Turns on or off media scan for the virtual disk. To turn media scan on, set this parameter to TRUE. To turn media scan off, set this parameter to FALSE. (If media scan is disabled at the storage array level, this parameter has no effect.)

mirrorCacheEnabled
Turns on or off the mirror cache. To turn the mirror cache on, set this parameter to TRUE. To turn the mirror cache off, set this parameter to FALSE.

modificationPriority
Defines the priority for virtual disk modifications while the storage array is operational. Valid entries are highest, high, medium, low, or lowest

owner
The RAID controller module that owns the virtual disk. Valid RAID controller module identifiers are a or b where a is the RAID controller module in slot A and b is the RAID controller module in slot B. Use this parameter only if you want to change the virtual disk owner.

readCacheEnabled
This parameter turns on or off the read cache. To turn the read cache on, set this parameter to TRUE. To turn the read cache off, set this parameter to FALSE.

writeCacheEnabled
This parameter turns on or off the write cache. To turn the write cache on, set this parameter to TRUE. To turn the write cache off, set this parameter to FALSE.

cacheReadPrefetch
This parameter turns on or turns 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.

addCapacity
This parameter increases 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 units are bytes.

addPhysical Disks
This parameter adds new physical disks to the virtual disk. Specify the enclosure ID and slot ID for each physical disk you assign to the virtual disk. Enclosure ID values are 0 to 99. Slot ID values are 1 to 32. Enclose the enclosure ID and slot ID values in square brackets ([ ]). Use this parameter with the addCapacity parameter if you need to specify additional physical disks to accommodate the new size.

consistencyCheckEnabled
This parameter turns on or off redundancy checking during a media scan. To turn redundancy checking on, set this parameter to TRUE. To turn redundancy checking off, set this parameter to FALSE.

segmentSize
This parameter specifies the amount of data (in kilobytes) 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
This parameter specifies the new name you want to give an existing virtual disk. Enclose the new virtual disk name in double quotes (" ").

accessVirtualDisk
This parameter defines the logical unit number for the access virtual disk. (The logical unit number is the only property you can set for the access virtual disk.

logicalUnitNumber
This parameter defines specific virtual disk-to-LUN mappings to an individual host or assigns the host to a host group.

host
This parameter specifies the name of the host to which the virtual disk is mapped. Enclose the host name in double quotes (" ").

hostGroup
This parameter specifies the name of the host group to which the virtual disk is mapped. Enclose the host group name in double quotes (" "). defaultGroup is the host group that contains the host to which the virtual disk is mapped.

Notes

When you use this command, you can specify on or more of the parameters. You do not, however, need to use all of the parameters.

You can apply the following parameters to only one virtual disk at a time:

addCapacity
segmentSize
userLabel
logicalUnitNumber

Setting addCapacity, addPhysical Disks, or segmentSize 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 display the progress of long running operations, use the show virtualDisk actionProgress command.

The access virtual disk is the virtual disk in a SAN environment used for in-band communication between the storage management software and the storage array RAID controller module. This virtual disk uses a LUN address and consumes 20 MB of storage space that is not available for application data storage. An access virtual disk is required only for in-band managed storage arrays. If you specify accessVirtualDisk, the only property you can set is the logicalUnitNumber.

Valid values for the cache flush modifier are:

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 will be flushed based on other criteria managed by the RAID controller module.

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 uninterruptable power supply (UPS) or other back-up power source, you can lose data if the storage array power fails. This parameter has no affect if write caching is disabled.

Modification priority defines the amount of system resources used when modifying virtual disk properties. If you select the highest priority level, the virtual disk modification uses the most system resources, which decreases performance for host data transfers.

Cache read prefetch enables the RAID controller module to copy additional data blocks into cache while the RAID controller module reads and copies data blocks requested by the host from 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 number of additional data blocks that the RAID controller module reads into cache is determined by the storage array configuration settings that you use. Valid values for the cacheReadPrefetch parameter are TRUE or FALSE.

The size of a segment determines how many data blocks 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 blocks 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 provided by the RAID controller module at run time. If the value you enter is not valid, the RAID controller module returns a list of valid values. For optimal performance in a multi-user database or file system storage environment, set your segment size to minimize the number of physical disks needed to satisfy a data transfer request. 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 a single-user large data transfer environment (such as multi-media) performance is maximized when a single data transfer request is serviced with a single data stripe. (A data stripe is the segment size multiplied by the number of physical disks in the disk group that are used for data transfers.) In this case, multiple disks are used for the same request, but each disk is only accessed once.

If you set the cache block size to 16, then you cannot create a virtual disk with a segment size of 8.

Minimum Firmware Level

5.00 adds the addCapacity parameter

Parameter	Description
`allVirtual Disks`	Use this parameter to define the properties for all virtual disks in the storage array.
`virtualDisk` or `virtual disks`	This parameter specifies 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 virtual diskNames parameter). Enclose the virtual disk name in double quotation marks (??? ???) inside of square brackets ([ ]).
`virtualDisk`	This parameter specifies the World Wide Name (WWN) of the virtual disk for which you are setting properties. You can use the WWN instead of the virtual disk name to identify the virtual disk. Enclose the WWN in angle brackets (< >).
`cacheFlushModifier`	Maximum amount of time that data for the virtual disk remains in cache before being flushed to physical storage. Valid values are listed in the following "Notes" section.
`cacheWithoutBatteryEnabled`	Turns on or off caching without batteries. To turn caching without batteries on, set this parameter to TRUE. To turn caching without batteries off, set this parameter to FALSE.
`mediaScanEnabled`	Turns on or off media scan for the virtual disk. To turn media scan on, set this parameter to TRUE. To turn media scan off, set this parameter to FALSE. (If media scan is disabled at the storage array level, this parameter has no effect.)
`mirrorCacheEnabled`	Turns on or off the mirror cache. To turn the mirror cache on, set this parameter to TRUE. To turn the mirror cache off, set this parameter to FALSE.
`modificationPriority`	Defines the priority for virtual disk modifications while the storage array is operational. Valid entries are highest, high, medium, low, or lowest
`owner`	The RAID controller module that owns the virtual disk. Valid RAID controller module identifiers are a or b where a is the RAID controller module in slot A and b is the RAID controller module in slot B. Use this parameter only if you want to change the virtual disk owner.
`readCacheEnabled`	This parameter turns on or off the read cache. To turn the read cache on, set this parameter to TRUE. To turn the read cache off, set this parameter to FALSE.
`writeCacheEnabled`	This parameter turns on or off the write cache. To turn the write cache on, set this parameter to TRUE. To turn the write cache off, set this parameter to FALSE.
`cacheReadPrefetch`	This parameter turns on or turns 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.
`addCapacity`	This parameter increases 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 units are bytes.
`addPhysical Disks`	This parameter adds new physical disks to the virtual disk. Specify the enclosure ID and slot ID for each physical disk you assign to the virtual disk. Enclosure ID values are 0 to 99. Slot ID values are 1 to 32. Enclose the enclosure ID and slot ID values in square brackets ([ ]). Use this parameter with the addCapacity parameter if you need to specify additional physical disks to accommodate the new size.
`consistencyCheckEnabled`	This parameter turns on or off redundancy checking during a media scan. To turn redundancy checking on, set this parameter to TRUE. To turn redundancy checking off, set this parameter to FALSE.
`segmentSize`	This parameter specifies the amount of data (in kilobytes) 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`	This parameter specifies the new name you want to give an existing virtual disk. Enclose the new virtual disk name in double quotes (" ").
`accessVirtualDisk`	This parameter defines the logical unit number for the access virtual disk. (The logical unit number is the only property you can set for the access virtual disk.
`logicalUnitNumber`	This parameter defines specific virtual disk-to-LUN mappings to an individual host or assigns the host to a host group.
`host`	This parameter specifies the name of the host to which the virtual disk is mapped. Enclose the host name in double quotes (" ").
`hostGroup`	This parameter specifies the name of the host group to which the virtual disk is mapped. Enclose the host group name in double quotes (" "). `defaultGroup` is the host group that contains the host to which the virtual disk is mapped.

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 will be flushed based on other criteria managed by the RAID controller module.