Checklist 3: Adding disk units to an existing input/output adapter

Use this checklist if you plan to protect some or all of the new disk units with device parity protection.

If you do not plan to protect any of the new disk units, use Checklist 2: Adding disk units without device parity protection.

You can use this procedure whether or not you have mirrored protection on your system because you start device parity protection before you add the disk units to an auxiliary storage pool (ASP). You can use either dedicated service tools (DST) or system service tools (SST) to perform the tasks in this checklist. If you use SST, you can perform the tasks while your system is active. If you use DST, you must stop your system to perform the tasks in this checklist.

Before you begin, make a copy of this checklist. Fill in the appropriate areas as you or the service representative perform the configuration tasks. This checklist provides an important record of your actions. It might help you diagnose any problems that occur.

Attention: When you perform the tasks in this checklist, the system moves large amounts of data. Make sure that you have saved your system completely in the event that you need to recover from an error situation.

Most tasks in Table 1 include references to other topics in this document. Refer to these topics if you need more information about how to perform a particular task.

Table 1. Adding disk units to an existing IOA–Tasks
Task	What to do	Where to read more about it
___ Task 1	Physically attach disk units. This is normally done by a service representative.
___ Task 2	Start DST or SST.	Starting dedicated service tools or Starting system service tools.
___ Task 3	Print your current disk configuration.	Displaying your disk configuration.
___ Task 4	For the disks that you want to parity protect, do one of the following steps: Start device parity protection. Include the disk units in an existing device parity set.	Starting device parity protection and Including a disk unit in device parity protection.
___ Task 5	Add nonconfigured disk units to the correct ASPs. See note 1 and note 2.	Adding disk units to an existing auxiliary storage pool.
___ Task 6	If you created a new ASP on your system when you added disk units, the system set the storage threshold of the ASP to 90%. If you want a different threshold, change it.	Changing the storage threshold for an auxiliary storage pool.
___ Task 7	Specify the storage threshold for the system ASP. If you use the QSTGLOWLMT and QSTGLOWACN system values, you can prevent the system ASP from filling to capacity and causing an abnormal shutdown.	Changing the storage threshold for the system auxiliary storage pool.
___ Task 8	Verify that your disk configuration is correct and print a copy for your records.	Displaying your disk configuration.
___ Task 9	End DST or SST.	Stopping dedicated service tools or Stopping system service tools.
¹ You can add the disk units to an existing ASP or you can add them to a new ASP. ² If you are adding disk units to an ASP that has mirrored protection and the new disk units do not have device parity protection, you must add pairs of disk units that have identical capacities.