Learn how to add additional disk units to 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

The Independent Auxiliary Storage Pool (IASP) volumes of your high availability configuration might require additional storage capacity. If your established SVC environment requires additional disk units for more capacity, complete the following procedure to add units to the IASP in an SVC environment.

Procedure

1. To add new disk units to the independent ASP, first create the new disk units (LUNs) on the source SVC storage controller.

2. Assign these new disk units on the source SVC storage controller to the source/production IBM i.

3. Initialize and format the new non-configured units on the source/production IBM i.

Initializing and formatting non-configured units

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 3: Work with disk unit recovery.
Select option 2: Disk unit problem recovery procedures.
Select option 1: Initialize and format disk unit.
Select option 1 on the new non-configured disk units that you want to be added to the ASP.
Press F10 to confirm the choice to initialize and format the disk units.
Exit the System Service tools.

4. If the configuration contains either Metro Mirror or Global Mirror configure replication set up the target SVC storage controller and IBM i.

Configure Metro Mirror or Global Mirror Replication

Create the new disk units on the target SVC storage controller.
Create the remote copy relationship(s).

Important: Ensure that when creating the relationship, that you do not check the box indicating that the volumes are already synchronized

3. Start the remote copy relationship(s).
4. Wait for the remote copy relationship state to be either ‘Consistent Copying’ or ‘Consistent Synchronized’ depending on the configuration.

5. Stop the new remote copy relationship(s). Do not allow secondary read/write access.

6. Use the Change SVC Session (CHGSVCSSN) command with OPTION(*SUSPEND) to suspend the replication.
7. Add the remote copy relationship to the existing remote copy consistency group used by the environment.

Use the Display SVC Session (DSPSVCSSN) display to find the remote copy consistency group name.

8. Use the Change SVC Session (CHGSVCSSN) command with OPTION(*RESUME) to resume the replication.

9. Assign these new disk units on the target SVC storage controller to the target IBM i.

Note: The disk unit resource names on the target system may be in the form DMPxxxx or DPHxxxx, where xxxx is a numeric value. Either value is okay, and disk resources starting with DPHxxxx will be converted to DMPxxxx upon performing PowerHA operations.

5. On the production system, add the new units to the ASP using SST.

Adding new disk units to an ASP

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 2: Add units to ASPs.
Select option 3: Add units to existing ASPs.
Enter the ASP number of the existing ASP to add units to, using the ASP number of the independent ASP.

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.

8. Confirm the choice to add disk units.

9. Exit the System Service Tools.

6. Update the source copy description using the Change SVC Copy Description (CHGSVCCPYD) command.

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 7 updates the second copy description to resolve this.

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

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

9. If the configuration contains FlashCopy, perform the following steps:

a. create the same number and size of disk units in the storage for the target copy of the FlashCopy and assign the disk units to the FlashCopy target node.

b. Update any FlashCopy target copy descriptions to contain new disk units for use in the FlashCopy environment. PowerHA will begin utilizing the new disk units during the next FlashCopy operation.

Results

The expanded storage in the environment on your IBM i partition is available for use.

Adding Disk Units in an SVC Environment

Before you begin

About this task

Procedure

Results