This checklist shows the sequence of tasks that you use to remove one or more disk units from an input/output adapter that is capable of device parity protection. These tasks apply when the disk pools that contain the disk units have mirrored protection and when the disk units have device parity protection. Use these tasks when your are permanently removing disk units from your system. Do not use these tasks when you are repairing or replacing a failed disk unit. You must restart your server to the dedicated service tools (DST) mode to perform the tasks in this checklist.
Before you begin
Print a copy of this checklist. Check off the configuration tasks as you perform them. This checklist provides an important record of your actions. It may help you diagnose any problems that occur.
| Task | What to do | Where to learn more |
|---|---|---|
| 1.___ | Display your current disk configuration. | Evaluate the current configuration |
| 2.___ | Calculate the space requirements for the disk pools that are involved in disk removal. | Calculate disk space requirements |
| 3.___ | Use option 21 from the Save menu to save your entire system. | Save your server with the GO SAVE command |
| 4.___ | Restart your server and select the option to use dedicated service tools (DST). | "How to Start Dedicated Service Tools (DST)"
in Backup and
Recovery  . From the taskpad in iSeries™ Navigator, select Open iSeries Navigator
Service Tools. |
| 5.___ | Remove disk units that you plan to remove from the system. | Move and remove disk units |
| 6.___ | Exclude the disk units from device parity protection. If you were successful in excluding the disk units, skip to task 9. Otherwise, continue to task 7. | Exclude disk units from a parity set |
| 7.___ | Stop mirrored protection for the disk pools that will have disk units removed. When you stop mirrored protection, one disk unit from each mirrored pair becomes unconfigured. You need to stop mirrored protection only if the disk pool contains other disk units that are attached to the IOP and have device parity protection. | Stop mirrored protection |
| 8.___ | Stop device parity protection for all the disk units in the IOP. | |
| 9.___ | Physically remove disk units. This is normally done by a service representative. If you stopped device parity protection in task 8, continue with task 10. If you did not stop device parity protection, skip to task 14. | Â |
| 10.___ | Start device parity protection again. | Start device parity protection |
| 11.___ | Add unconfigured disk units to the correct disk pools. These disk units became unconfigured when you stopped mirrored protection in task 7. | Add a disk unit or disk pool |
| 12.___ | If you created a new disk pool on your system when you added disk units, the system set the storage threshold of the disk pool to 90%. If you want a different storage threshold for any disk pool, you can change it. | Set the threshold of a disk pool |
| 13.___ | Start mirrored protection for the disk pools that had mirrored protection stopped in task 7. | Start mirrored protection |
| 14.___ | Verify that your disk unit configuration is correct. | Evaluate the current configuration |
| 15.___ | Print your disk configuration to have available in case a recovery situation occurs. | Print your disk configuration |