Acer R910 manual Memory mirroring, To configure memory mirroring

172 Appendix B: Memory configuration options

Memory mirroring

Memory mirror requires either two or four same size memory boards and provides redundancy at the cost of halving the effective memory size. The memory configuration allows for the hot-replacement of an existing board for a board containing an equal amount of memory or the hot-addition of two memory boards to a pair of empty memory board slots only.

A pair of memory boards in memory mirror mode forms a redundant group. One of the memory boards is designated the primary image and the other the secondary image. For memory writes, the write request is issued to both boards. For memory reads, the read request is issued to the primary memory board. In the event of a detected uncorrectable error, the primary and secondary images switches with each other and the failed image cannot become the primary image again until the failed DIMMs have been replaced and the image re-built. The first redundant group consists of memory board A mirrored with memory board B. The second redundant group consists of memory board C mirrored with memory board D. The BIOS sets the memory board mirror LED to indicate that the memory board is operating in the memoy mirror mode.

To configure memory mirroring:

1Do either option below:

• Run BIOS setup. See “Entering BIOS setup” on page 96.

- or -

aDuring system bootup, enter the System Options Menu. See “System options menu” on page 90.