Modifying a rank

Complete this task to modify a rank using the DS CLI

1. Issue the lsrank command to generate a report that lists the status of the ranks that are associated with the storage unit. Enter the lsrank command at the dscli command prompt with the following parameters and variables:

   dscli>lsrank -dev storage_unit_ID -l  

   Notes:

   1. The report that is generated by this example provides a list of all ranks; however, the storage type is mixed between fixed block and CKD.
   2. You can narrow your report information to a specific storage type by adding the -stgtype [fb | ckd] parameter to your command.
2. Use the report to determine the rank or ranks you want to modify. The report contains details about the ranks that you must use to issue the chrank command for modifications.
3. Issue the chrank command to implement one of the following types of modifications:
   1. To designate a rank as reserved, enter the chrank command at the dscli command prompt with the following parameters and variables:

      dscli>chrank -dev storage_image_ID -reserve rank_ID

      Changing the rank configuration state to "reserved" designates that the extents that are associated with the rank are not eligible for allocation to a logical volume. However, the existing allocations remain in effect until the configuration state is changed to normal. In other words, the characteristics that the rank inherited from its parent array when it was originally assigned remain intact.

      Notes:

      1. You can specify a range of rank IDs or multiple rank IDs as long as you match the command usage criteria.
      2. You cannot change the configuration state of a reserved rank to "unassigned" without first releasing it.
   2. To release a rank from its reserved configuration state, enter the chrank command at the dscli command prompt with the following parameters and variables:

      dscli>chrank -dev storage_image_ID -release rank_ID

      When a rank is released from the configuration state of "reserved", it is designated with a configuration state of "normal".

   3. To remove a rank from its current extent pool and array assignment but not delete it, enter the chrank command at the dscli command prompt with the following parameters and variables:

      dscli>chrank -dev storage_image_ID -unassign rank_ID

      Notes:

      1. A rank must have a configuration state of normal before it can be changed to a configuration state of unassigned.
      2. A rank that is unassigned can be assigned to an array and extent pool of another storage configuration as long as the storage type is compatible: all fixed block or all CKD.