chrank

The chrank command assigns an unassigned rank to an extent pool, or removes an assigned rank from an extent pool. This command can also be used to change an assigned rank to an unassigned rank.

Read syntax diagramSkip visual syntax diagramchrank -dev storage_image_ID  -reserve  -release -unassign  -extpool  extentpool_ID  -quiet rank_ID   ...   "-"

Parameters

-dev storage_image_ID
(Optional) The storage image ID, which consists of manufacturer, machine type, and serial number. The storage image ID is required if you do not specify fully qualified IDs, do not set the devid variable in your profile or through the setenv command, and the HMC is aware of more than one storage image. Using the -dev parameter temporarily overrides any defined value for devid for the current command.
-reserve
(Optional) Changes the rank configuration state to Reserved if the rank is assigned to an extent pool, or changes the state to Unassigned Reserved if the rank is not assigned to an extent pool. If the rank is in the depopulating state, changing the configuration state to Reserved with the -reserve parameter stops the rank depopulation. In this case, data is not migrated back to the depopulation rank. Use the -release parameter to convert it back to the normal state and restart the depopulation later. The depopulation process starts from where it left off when the abort was triggered.
Note: Versions of the DS CLI before Release 6.1 fail if you use the -reserve parameter on Release 6.1 or later DS8000® storage systems when the rank is in the unassigned state. These DS CLI versions cannot handle the Unassigned Reserved state.
-release
(Optional) Changes the rank configuration state from Unassigned Reserved to Unassigned, or from Reserved, Normal, or Depopulation Error to Normal.
-unassign
(Optional) Changes the rank configuration state to Unassigned by removing the rank from the extent pool. If extents exist on this rank are used to provision a volume, the unassign process normally fails. If the Easy Tier LIC feature is active, then the rank configuration state is set to Depopulating while the extents are migrated to other ranks in the same extent pool. If the depopulation is successful, the rank configuration state is set to Unassigned. If it is not successful, the state is set to Depopulation Error.
Notes:
  1. If the rank enters the Depopulating configuration state, the time that is required to depopulate the rank depends on the number of allocated extents; it might take a long time before the rank enters the Unassigned state. When this situation occurs, a confirmation prompt is given, but can be suppressed with the -quiet parameter.
  2. Versions of the DS CLI before Release 6.1 fail if you use the -unassign parameter on Release 6.1 or later DS8000 storage systems with allocated extents. If you use these previous versions of the DS CLI, manually delete or migrate any volumes that use these ranks before you use the -unassign parameter.
  3. The -extpool and -unassign parameters cannot be used together.
-extpool extentpool_ID
(Optional) Assigns the rank to an extent pool. Accepts either a fully qualified extent pool ID including storage image ID or a shortened version if the -dev parameter is used. The shortened version is a four-digit decimal number with no leading zeroes, prefixed with the letter P.
Note: The -extpool and -unassign parameters cannot be used together.
-quiet
(Optional) Turns off the rank modification confirmation prompt for this command.
rank_ID ... | -
(Required) Whether one or more ranks to be modified. Accepts either a fully qualified rank ID, or a rank number if the -dev parameter is used. A rank number is a four-digit decimal number with no leading zeroes, prefixed by the letter R.
To specify a range of rank IDs, separate the rank IDs with a hyphen.
You must separate multiple rank IDs or ranges of rank IDs with a blank space between each ID or range of IDs.
The ellipsis (...) indicates that, optionally, you can specify multiple values. If you use the dash (-), the specified value is read from standard input. You cannot use the dash (-) while you are in the DS CLI interactive command mode.

Example: Assigning a rank to an extent pool

dscli> chrank -dev IBM.2107-75FA120 -extpool P101 -quiet R2
Output
Rank IBM.2107-75FA120/R2 successfully modified.