chvdisk

Parameters

-namenew_name_arg

(Optional) Specifies a new name to assign to the volume. You cannot use this parameter with the -rate or -udid parameters. This parameter is required if you do not use the -rate or -udid parameters.

Note: Do not use this parameter with file system volumes.

-cachereadwrite | readonly | none

(Optional) Specifies the caching options for the volume. Valid entries are:

• readwrite to enable the cache for the volume
• readonly to disable write caching while allowing read caching for a volume
• none to disable the cache mode for the volume

The default is readwrite.

Remember: If you do not specify the -cache parameter, the default value (readwrite) is used.

-force

(Optional) The force parameter can only be used for changing the caching mode. Use the force parameter with the cache parameter to specify that you want the system to change the cache mode of the volume even if the I/O group is offline. This option overrides the cache flush mechanism.

Attention: If the force parameter is used for changing the caching mode, the contents of the cache are discarded and the volume might be corrupted by the loss of the cached data. This could occur if the system is able to destage all write data from the cache or not. The force parameter should be used with caution.

Important: Using the force parameter might result in a loss of access. Use it only under the direction of your product support information.

-ratethrottle_rate-unitmb

(Optional) Specifies the I/O governing rate for the volume, which caps the amount of I/O that is accepted. The default throttle_rate units are I/Os. By default the throttle_rate is disabled. To change the throttle_rate units to megabits per second (MBps), specify the -unitmb parameter. The governing rate for a volume can be specified by I/Os or by MBps, but not both. However, you can set the rate to I/Os for some volumes and to MBps for others. When the Input/Output Operations Per Second (IOPS) limit is configured on a volume, and it is smaller than 100 IOPS, the throttling logic rounds it to 100 IOPS. Even if throttle is set to a value smaller than 100 IOPs, the actual throttling occurs at 100 IOPs.

Note: To disable the throttling on a specific volume, set the throttle_rate value to zero.

You cannot use this parameter with the -name or -udid parameters.

-udidvdisk_udid

(Optional) Specifies the unit number (-udid) for the disk. The vdisk_udid is an identifier that is required to support OpenVMS hosts; no other systems use this parameter. Valid options are a decimal number from 0 to 32 767 or a hexadecimal number from 0 to 0x7FFF. A hexadecimal number must be preceded by 0x (for example, 0x1234). If you do not use the -udid parameter, the default -udid is 0.

You cannot use this parameter with the -name parameters.

-warningdisk_size | disk_size_percentage%

(Optional) Generates a warning when the used disk capacity on the thin-provisioned copy first exceeds the specified threshold. You can specify a disk_size integer, which defaults to MBs unless the -unit parameter is specified; or you can specify a disk_size%, which is a percentage of the volume size. To disable warnings, specify 0 or 0%.

-unitb | kb | mb | gb | tb | pb

(Optional) Specifies the data units to use for the -warningdisk_size parameter. The default unit value is MB.

-autoexpandon | off

(Optional) Specifies whether thin-provisioned volume copies automatically expand their real capacities by allocating new extents from their storage pool. To use this parameter, the volume must be thin-provisioned.

-copyid

(Optional) Specifies the copy to apply the changes to. You must specify this parameter with the -autoexpand or -warning parameter. The -copy parameter is required if the specified volume is mirrored and only one volume copy is thin-provisioned. If both copies are thin-provisioned and the -copy parameter is not specified, the specified -autoexpand or -warning parameter is set on both copies.

-primarycopy_id

(Optional) Specifies the primary copy. Changing the primary copy only takes effect when the new primary copy is online and synchronized. If the new primary is online and synchronized when the command is issued, the change takes effect immediately. You cannot change the volume's primary copy if that primary copy has its autodelete flag is set to yes (on).

Important: You cannot use this parameter with a volume that is fast formatting.

-syncrate syncrate

(Optional) Specifies the copy synchronization rate. A value of zero (0) prevents synchronization. The default value is 50. See Table 1 for the supported -syncrate values and their corresponding rates. Use this parameter to alter the rate at which the fully allocated volume or mirrored volume format before synchronization.

-easytieron | off

(Optional) Enables or disables the Easy Tier^® function.

-mirrorwriteprioritylatency | redundancy

(Optional) Specifies how to configure the mirror write algorithm priority. A change to the mirror write priority is reflected in the volume's view immediately and in the volume's behavior after all prior input and output (I/O) completes.

1. Choosing latency means a copy that is slow to respond to a write I/O becomes unsynchronized, and the write I/O completes if the other copy successfully writes the data
2. Choosing redundancy means a copy that is slow to respond to a write I/O synchronizes completion of the write I/O with the completion of the slower I/O in order to maintain synchronization.

vdisk_name | vdisk_id

(Required) Specifies the volume to modify, either by ID or by name.