IBM 8870 manual Active Memory, Memory scrubbing and Memory ProteXion, Memory mirroring

Active Memory

Active Memory is an IBM feature that improves the reliability of memory through memory mirroring, memory scrubbing, and the Memory ProteXion feature.

Memory scrubbing and Memory ProteXion

Memory scrubbing tests the memory at regular intervals to detect and report potential memory errors before they can cause server outages.

If a detected error is recoverable, the Memory ProteXion feature corrects the error and rewrites the data to another memory location on the same DIMM. The error is logged in the error log so that you can determine whether preventive maintenance is necessary.

If there are not sufficient undamaged memory locations that the data can be rewritten to, the error is unrecoverable. Other conditions can also cause unrecoverable errors. If a detected error is unrecoverable, LEDs on the Light Path Diagnostics panel are lit to indicate the failing DIMM.

You do not have to enable memory mirroring to use memory scrubbing and the

Memory ProteXion feature.

Memory mirroring

Memory mirroring stores data in memory port 1 and memory port 2 simultaneously. To support memory mirroring, you must install identical dual inline memory modules (DIMMs) in memory port 1 and memory port 2. For more information, see the section about installing memory modules in the Option Installation Guide on the IBM xSeries Documentation CD.

To enable memory mirroring through the Configuration/Setup Utility program, select Advanced Setup from the main menu, and then select Memory Settings. For more information about using the Configuration/Setup Utility program, see Chapter 2, “Configuring the server,” on page 17.

When memory mirroring is enabled, BIOS will only report half of the installed memory. For example, if you have 64 GB of memory installed and memory mirroring is enabled, BIOS will only report 32 GB of memory.

Note: To use the hot-add memory feature, memory mirroring must be disabled in the BIOS code.

The UpdateXpress program

The UpdateXpress program is available for most xSeries servers and server options. It detects supported and installed device drivers and firmware in your server and installs available updates. You can download the UpdateXpress program from the Web at no additional cost, or you can purchase it on a CD. To download the program or purchase the CD, go to http://www.ibm.com/pc/ww/eserver/xseries/serverguide/xpress.html.

Chapter 1. Introducing the IBM xSeries 445 server 7