IBM 71455DU manual Active Memory

Table 4. Alternate memory card installation sequence (continued)

Memory card order	Memory card	DIMM pair
Fourth	4	1 and 3
		2 and 4

Table 5. Memory card installation sequence for memory-mirrored configuration

Memory card order	Memory card	DIMM pair
First	1	1 and 3
	3	1 and 3
Second	2	1 and 3
	4	1 and 3
Third	1	2 and 4
	3	2 and 4
Fourth	2	2 and 4
	4	2 and 4

vThere are two memory power buses split between the four memory cards. Memory cards 1 and 2 are on power bus 1, and memory cards 3 and 4 are on power bus 2. If memory mirroring is enabled, you can hot-replace one memory card at a time on each memory power bus.

vIf a problem with a DIMM is detected, light path diagnostics will light the system-error LED on the front of the server, indicating that there is a problem and guide you to the defective DIMM. When this occurs, first identify the defective DIMM; then, remove and replace the DIMM.

The following illustration shows the LEDs on the memory card:

Memory Port Power

Error

Memory Hot-Swap Enabled

Memory Hot-Swap Enabled LED: When this LED is lit, it indicates that hot-swap memory is enabled.

Error LED: When this LED is lit, it indicates that a memory card or DIMM has failed.

Memory Port Power LED: When this LED is off, it indicates that power is removed from the port and that you can remove the memory card and replace a failed DIMM. This LED will also turn off when the release levers are opened.

Note: Add odd numbered DIMMs to each available memory card first, then add the even numbered pairs.

Active Memory

Active Memory is an IBM technology that improves the reliability of the DIMMs through the memory mirroring, memory scrubbing, and Memory ProteXion™ features.

Chapter 2. Installing options 33