Memory Problems - IBM System x3850 X6 Installation And Service Manual

Memory problems

Use this information to solve memory problems.
Table 44. Symptoms and user actions for memory problems
v Follow the suggested actions in the order in which they are listed in the Action column until the problem is
solved.
v See Chapter 5, "Parts listing, System x3850 X6 and x3950 X6 Types 3837 and 3839," on page 205 to determine
which components are customer replaceable units (CRU) and which components are field replaceable units
(FRU).
v If an action step is preceded by (Trained service technician only), that step must be performed only by a Trained
service technician.
Symptom
The amount of system memory
that is displayed is less than the
amount of installed physical
memory.
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System x3850 X6 and x3950 X6 Types 3837 and 3839: Installation and Service Guide
Action
Note: If you change memory, you must update the memory configuration in the
Setup utility (see "Using the Setup utility" on page 126 for more information). For
more information about installing DIMMs and DIMM population sequence, see
"Installing a memory module" on page 47, "Independent memory mode" on page
55, "Lockstep memory mode" on page 59, "Memory mirroring" on page 53, and
"Memory rank sparing" on page 54.
1. If the server was recently installed, moved, or serviced, make sure that all
DIMMs are seated correctly.
2. If a new DIMM has been installed recently, verify that you have not received
any configuration events in the event log. Otherwise, check the IMM event log.
If any DIMM configuration events are listed, resolve the DIMM event
problems first.
3. Make sure that:
v No error LEDs are lit on the operator information panel or on the compute
book.
v Memory mirroring does not account for the discrepancy (see "Memory
mirroring" on page 53).
v The memory modules are seated correctly (see "Removing a memory
module" on page 239 and "Replacing a memory module" on page 240).
v You have installed the correct type of memory (see "Installing a memory
module" on page 47).
v If you changed the memory, you updated the memory configuration in the
Setup utility (see "Using the Setup utility" on page 126).
v All banks of memory are enabled. The server might have automatically
disabled a memory bank when it detected a problem, or a memory bank
might have been manually disabled.
4. Check the POST event log:
v If a DIMM was disabled by a systems-management interrupt (SMI), replace
the DIMM.
v If a DIMM was disabled by the user or by POST, run the Setup utility and
enable the DIMM.
5. Run memory diagnostics (see "IBM Dynamic System Analysis" on page 173). If
an error is detected, follow the steps to correct the error.
6. Restart the server.