Memory Mirroring - IBM 7979B1U User Manual

To install a DIMM, complete the following steps.
1. Read the safety information that begins on page vii and "Installation guidelines"
2. Turn off the server and peripheral devices, and disconnect the power cord and
3. Remove the cover (see "Removing the cover" on page 31).
4. Remove the riser-card assembly (see "Removing the riser-card assembly" on
5. Remove the DIMM air baffle (see "Removing the DIMM air baffle" on page 36).
6. Open the retaining clip on each end of the DIMM connector.
7. Touch the static-protective package that contains the DIMM to any unpainted
8. Turn the DIMM so that the DIMM keys align correctly with the connector.
9. Insert the DIMM into the connector by aligning the edges of the DIMM with the
If you have other optional devices to install or remove, do so now. Otherwise, go to
"Completing the installation" on page 81.

Memory mirroring

You can configure the server to use memory mirroring. Memory mirroring stores
data in two pairs of DIMMs simultaneously. If a failure occurs, the memory controller
switches from the active pair to the mirroring pair. Memory mirroring reduces the
amount of available memory. Enable memory mirroring through the
Configuration/Setup Utility program. See "Configuration/Setup Utility menu choices"
on page 86 for details about enabling memory mirroring.
on page 28.
all external cables.
Attention: In a dc power environment, only trained service personnel other
than IBM service technicians are authorized to connect or disconnect power to
the dc power supply. See the documentation that comes with each dc power
supply.
Attention: To avoid breaking the retaining clips or damaging the DIMM
connectors, open and close the clips gently.
page 32).
metal surface on the server. Then, remove the DIMM from the package.
slots at the ends of the DIMM connector. Firmly press the DIMM straight down
into the connector by applying pressure on both ends of the DIMM
simultaneously. The retaining clips snap into the locked position when the DIMM
is firmly seated in the connector.
Important: If there is a gap between the DIMM and the retaining clips, the
DIMM has not been correctly inserted; open the retaining clips, remove the
DIMM, and then reinsert it.
Chapter 2. Installing optional devices
69