memory contents. Be aware that some of the total swap space may be supplied by disks that are attached to the board to be deleted. When making your assessment, be certain to also account for the swap space that will be lost.

■If the size of available memory (e.g., 1.5 gigabytes) is larger than the size of deleted memory (e.g., 1 gigabytes), the total size of available memory will be 0.5 gigabytes after deleting the system board.

■If the size of available memory (e.g., 1.5 gigabytes) is smaller than the size of deleted memory (2 gigabytes), the attempt to delete the system board will fail.

To determine the size of currently available swap area, execute the swap -s command on the OS and verify that the memory size is marked available. For details, refer to the Solaris man page swap(1M). Moreover, the size of physical memory of system board to be deleted and information on I/O devices connected can be confirmed by the showdevices(8) command. See Section 3.1.4, “Display Device Information” in Chapter 3, DR User Interface, or the showdevices(8) man page. Refer to Appendix B for a more complete example.

2.5.3Real-time Processes

The Solaris OS is temporarily suspended when a kernel memory board is deleted or moved. If your system has any real-time requirements (such as might be indicated by the presence of real-time processes), be aware that such a DR operation could significantly affect these processes.

2.5.4Memory Mirror Mode

The memory mirror mode is a function used to duplex memory to ensure the hardware reliability of memory. When memory mirror mode is enabled, the domain can continue operation even if a fault occurs in a part of memory (provided that the fault is recoverable).

Memory mirror mode cannot be set in some division types of PSB. Please see the SPARC Enterprise M4000/M5000/M8000/M9000 Servers XSCF User’s Guide for the availability of memory mirroring.

Enabling memory mirror mode does not restrict any DR functions. However, you must consider the domain configuration and operation when enabling memory mirror mode.

2-28SPARC Enterprise Mx000 Servers Dynamic Reconfiguration User’s Guide • September 2007