Deleting ranks from a storage configuration

Complete this task to remove ranks from a storage configuration using the DS CLI.

When you are using the DS CLI to delete ranks as part of a storage configuration deletion, the following sequential deletions must have already occurred:

Host access to the volumes of the configuration must have been removed. (Does not apply to a CKD configuration.)
The associated volume groups must have been removed. (Does not apply to a CKD configuration.)
The fixed block or CKD volumes that are part of the configuration must have been removed.
The LCUs (if you are removing a CKD configuration) must have been removed.

When you remove ranks using the DS CLI, there is an extended period of processing because the arrays and extent pools are unassigned from the ranks and the drives are formatted. During this processing, the arrays and extent pools are still shown with a status of assigned, even though you receive a confirmation message each time a rank has been deleted. The status for the arrays and extent pools do not change to "unassigned" until after the drives have been formatted.

Perform the following steps to remove ranks from a storage configuration:

Issue the lsrank command to obtain a list of the ranks that are associated with the storage configuration that is being deleted. Enter the lsrank command at the dscli command prompt with the following parameters and variables:
```
dscli>lsrank -dev storage_image_ID -l -stgtype [fb | ckd]
```
Look at the list and ensure that the ranks are in a state that allows them to be deleted. All the ranks need to have a data and configuration state of normal.
Issue the rmrank command to delete the ranks from the storage configuration. Enter the rmrank command at the dscli command prompt with the following parameters and variables:
```
dscli>rmrank -dev storage_image_ID rank_ID
```
Notes:
1. If you have multiple ranks that are being deleted, you might want to include the -quiet parameter in your command. This parameter suppresses the confirmation message that is issued for each rank that is deleted.
2. Deleting a rank or many ranks is a lengthy process because the array and extent pool assignments are unassigned and the disk drives are formatted.
  When a rank is unassigned from the array and extent pool, a confirmation messages is issued that indicates that the rank has been deleted. However, because of the formatting, the process is not complete. You cannot initiate any action on the arrays or extent pools until the formatting is completed.

Removing ranks from a storage configuration