Moreover, a system board that is pooled can be assigned to a domain only when it is registered on DCL. Pooled system boards must be properly managed.

You can add and delete system boards by combining the system board pooling function with the floating board, omit-memory, and omit-I/O options described in Section 2.2, “Conditions and Settings Using XSCF” on page 2-12.

2.1.4Checklists for System Configuration

This section describes the prerequisites and the checklists for configuring the system for DR.

1.Redundant Configuration of I/O Devices - Before a system board can be replaced, any I/O device connected to that board must be temporarily disconnected.

You should use redundant-configuration software to prevent any problem that might be caused by disconnection of an I/O device that would affect a job process. You should also confirm that the driver and software support DR before performing a DR operation.

2.Selection of PCI Cards Supporting DR - All PCI cards and I/O device interfaces on a system board must support DR. If not, you cannot execute DR operations on that system board. You must turn off the power supply to the domain before performing maintenance and installation.

3.Confirmation of DR Compliance of Drivers and Other Software - You must confirm that all I/O device drivers and software installed in the system support DR and allow the I/O device operations of DR.

You should also apply the latest patches to the drivers and other software before performing DR.

4.Allocation of Sufficient Memory and Distributed Swap Areas - You must allocate sufficient memory resources to be used when the memory on a system board is disconnected. Performing a DR operation with a high load already applied to memory may significantly lower job process performance and DR operability.

5.Consideration of Hardware Configuration and System Boards on Which Kernel Memory is Loaded - Before determining the hardware configuration and operations, you must understand how job processes are affected by DR operations on system boards on which CPUs, memory, and I/O devices are mounted.

You can perform DR operations on system boards that contain kernel memory. When disconnecting a system board on which kernel memory is loaded, DR copies kernel memory into the memory on another system board. The copy operation is based on the premise that the copy-destination system board does not already contain any kernel memory.

Chapter 2 What You Must Know Before Using DR 2-11