Removing a storage system by using the CLI

You can remove a storage system by using the command-line interface (CLI). The system supports both Fibre Channel and iSCSI-attached external storage systems.

During this procedure, you add a device, migrate data from the storage system, and remove the old MDisks.

An alternative to following this procedure is to migrate all of the volumes that are using storage in this storage pool to another storage pool. Using this method, you can consolidate the volumes in a single or new group. However, you can migrate only one volume at a time. The following procedure that is outlined migrates all the data through a single command.

You can also use this procedure to remove or replace a single MDisk in a storage pool. If an MDisk experiences a partial failure, such as a degraded array, and you can still read the data from the disk but cannot write to it, you can replace just that MDisk.

To remove a storage system:

Add the new storage system to your clustered-system configuration.
Enter the following command:
```
addmdisk -mdisk mdiskx:mdisky:mdiskz... mdisk_grp_name
```
where mdiskx:mdisky:mdiskz... are the names of new MDisks that have a total capacity that is larger than the decommissioned MDisks and mdisk_grp_name is the name of the storage pool that contains the MDisks that you want to decommission.
You now have a storage pool that you want to decommission and the new MDisks.
Ensure that the capacity of the new MDisks is the same or exceeds that of the old MDisks before you proceed to step #svc_decommissioningstorageconcli_21alnw/forcedelete.
Enter the following command to force the deletion of the old MDisks from the storage pool:
```
rmmdisk -force -mdisk mdiskx:mdisky:mdiskz... mdisk_grp_name
```
Where mdiskx:mdisky:mdiskz... are the old MDisks that you want to delete and mdisk_grp_name is the name of the storage pool that contains the MDisks that you want to delete. Depending upon the number and size of the MDisks, and the number and size of the volumes that are using these MDisks, this operation takes some time to complete, even though the command returns immediately.
Check the progress of the migration process by entering the following command:
```
lsmigrate
```
When all the migration tasks are complete, for example, the command in step #svc_decommissioningstorageconcli_21alnw/checkprog returns no output, verify that the MDisks are unmanaged.
Access the storage system and unmap the LUNs from the ports.
Note: You can delete the LUNs if you no longer want to preserve the data that is on the LUNs.
Enter the following CLI command:
```
detectmdisk
```
Verify that all MDisks are deleted for the storage system that you want to decommission.
If you are removing an iSCSI-attached storage system, complete these additional steps:
1. Verify the controller ID for the storage system that you are removing by entering the following command:
```
lscontroller
```
2. Enter the following command:
```
lsiscsistorageport
```
  In the results that display, check the output for the port IDs that correspond with the controller IDs that were listed when you entered the lscontroller command.
3. Remove the iSCSI storage port IDs that correspond to the storage system that you are decommissioning by entering the following command:
```
rmiscsistorageport
```
Remove the storage system from the SAN so that the ports can no longer access the storage system.