Learn how to remove disk units from an existing SVC configuration (including configurations using IBM FlashSystems or IBM Storwize storage devices)

Before you begin

These steps assume the user has experience configuring and managing an IBM® Spectrum Virtualize-based storage device and has a functioning configuration running.

Required PTF Group: These steps require the following PTF groups on all partitions in the PowerHA environment:

7.4: SF99666 Level 6
7.3: SF99876 Level 14
7.2: SF99776 Level 17

About this task

In some instances, you may want to remove storage from your Independent Auxiliary Storage Pool (IASP). This may be to allocate the storage to other environments or to replace the units with ones of a different size later on. Complete the following procedure to add units to the IASP in an SVC environment.

Procedure

If the configuration contains FlashCopy, end any currently active FlashCopy sessions using the ENDSVCSSN command.
Remove the volume from the IASP on the source/production IBM i.

Removing disk units from an IASP

From the IBM i command line, type STRSST and press enter to start System service tools (SST).
Sign on to SST with your service tools user ID and password.
Select option 3: Work with disk units.
Select option 2: Work with disk configuration.
Select option 12: Work with removing units from configuration.
Select option 3: Remove units from configuration.
Find the unit(s) you wish to remove, and select option 4 on those units.

Finding the ASP Number

The units are listed by ASP number. To find the ASP number of the existing IASP, use the Display ASP Status (DSPASPSTS) command. The ASP number will appear in the ASP Device field near the top left of the screen.

Determining the Unit on the Storage

If the units are attached to the system with either Physical Fibre Channel or with Virtual Fibre Channel, the disk unit serial number can be used to correlate the disk unit with the appropriate disk unit on the external storage device. In the example below unit 4003, with serial number YF524F000032, matches up with volume ID 48 in the storage. The UID ends with 000032.

8. When asked to confirm, press enter to confirm the removal of the units.

9. The remove operation will happen in the background. Use option 2 to display the status of the remove operation.

Important: Wait until the status screen shows the text No remove operation is active before continuing on to the next step, using the F5 key to refresh the screen.

10. Once done, display the disk configuration to verify that the expected disk is no longer in the IASP.

3. If the configuration contains either Metro Mirror or Global Mirror, deconfigure replication for the volumes that were removed. If the environment does not contain either Metro Mirror or Global Mirror, skip to step 8.

Deconfiguring Metro Mirror or Global Mirror Replication

On the storage device expand Copy Services and then click on Remove Copy.
Expand the consistency group that the volume was a part of.

Finding the Remote Copy Consistency Group
The remote copy consistency group name is displayed on the DSPSVCSSN panel within PowerHA, as well as via the QHASM.SESSION_INFO table function.

3. Right-click on the relationship that represents the volume to be removed and select delete.

4. Enter the number of relationships to be deleted.

5. Check the box: Delete the relationship even when the data on the target volume is inconsistent, or if the target volume has other dependencies.

4. Repeat this process for any additional volumes.

4. Update the source copy description using the Change SVC Copy Description (CHGSVCCPYD) command. When updating the vdisk range in the copy description, update the ranges so that they no longer contain the removed volumes.

Tip: The joblog for the command will contain the following diagnostic message:
Message . . . . : The quantity of logical units does not match.
Cause . . . . . : The quantity of logical units specified in auxiliary
storage pool (ASP) copy description &1 does not match the quantity of
logical units specified in ASP copy description &2. All operations
performed on ASP session &3 will fail until the quantity of logical units in
both ASP copy descriptions match.
Recovery . . . : Update the quantity of logical units in one or both ASP
copy descriptions.

Step 5 updates the second copy description to resolve this.

5. Update the target copy description using the Change SVC Copy Description (CHGSVCCPYD) command.

6. Verify with the Display SVC Session (DSPSVCSSN) command that replication is currently active for the session.

7. Verify the target IASP is still usable by using the DETACH operation to test the target copy.

Testing the Target Copy using Detach

Use the Change SVC Session (CHGSVCSSN) command with the *DETACH option
Vary on the IASP on the target node to verify the vary on of the IASP is successful
Once verified, vary off the IASP on the target node
Use the Change SVC Session (CHGSVCSSN) command with the *REATTACH option to restart replication

8. If the configuration contains FlashCopy, update any FlashCopy target copy descriptions by using the CHGSVCCPYD command to remove the disks that are no longer part of the configuration.

9. The non-configured units can now be removed from the IBM i, and optionally deleted from the storage device if no longer needed.

Results

The removed disk units are now listed under the non-configured units. These non-configured units can now be removed from the IBM i, and optionally deleted from the storage device if no longer required.

Removing Disk Units in an SVC Environment

Before you begin

About this task

Procedure

Results