Installation guide

IBM Eserver xSeries 366 Technical Introduction 15
To easily identify whether hot-swap is enabled and the status of power to the memory card,
each memory card has a green
memory hot-swap enable LED, and a green memory port
power
LED on the top panel of the memory card, as shown in Figure 9 on page 14. The
memory card has eject levers with sensors, so that the system can recognize when a memory
card is being removed and power down that card’s slot accordingly.
The overall process to hot-swap a failed DIMM is as follows:
1. Verify that memory mirroring and hot-swap are enabled by checking the
memory hot-swap
enable
LED on the memory cards.
2. When a DIMM fails, you will be alerted via the memory LED on the light path diagnostics
panel (and by other means via the service processor if this has been configured).
3. Locate the memory card with the failed DIMM by using the Error LED on the memory card.
4. Remove the memory card containing the failed DIMM.
5. Press the button on the memory card to identify which DIMM has failed. The LED next to
the failed DIMMs lights up.
6. Replace the failed DIMM and reinsert the memory card.
For a more detailed description of how to correctly hot-swap memory and which sequence to
follow, see the x366 User’s Guide.
Hot-add memory
The hot-add memory feature enables you to add DIMMs without turning off the server. This
section shows the requirements for enabling the hot-add memory feature on the server.
The requirements are as follows:
򐂰 Operating system support: Adding usable system memory to a running operating system
requires operating system support. This is done via an ACPI sequence. Currently, the only
operating system that has this capability and is supported on the x366 is Windows Server
2003, Enterprise Edition.
򐂰 Memory hot-add must be specifically enabled in the BIOS setup. When this is done, the
system allocates blank windows of memory space for future memory additions. By
enabling hot-add, memory mirroring will automatically be disabled.
򐂰 Memory cards 3 and 4 must not be installed yet because these are the
only ones that can
be hot-added.
򐂰 If only one memory card is installed (memory card 1) prior to the hot-add operation, then
only one additional memory card may be added in slot 3.
򐂰 If two memory cards (1 and 2) are already in the system, then two additional memory
cards
must be added in slots 3 and 4. The card in slot 4 must be inserted first because
power to the second bus will be applied after card 3 is inserted and closed.
򐂰 The DIMMs must be added two at a time (matched pairs) and they must also match the
equivalent pair of DIMMs on the matching memory card on the other power bus.
򐂰 A minimum of 4 GB of memory must be installed in the server in order for hot-add memory
to be available. Additionally, for 32-bit operating systems, the Physical Address Extension
(PAE) mode has to be enabled to take advantage of the additional memory.
Note: Hot-add and hot-swap are mutually exclusive. You can enable only one of these
features.