Troubleshooting
Problem
System x3630M4/x3530M4 may report uncorrectable bus error on Central Processing Unit (CPU) and uncorrectable error on memory while performing excessive memory usage application or memory diagnostic. The error from the Integrated Management Module (IMM)chassis event log is as follows and results in a system restart. CHASSIS:(12/23/2014 02:23:11) An Uncorrectable Bus Error has occurred on bus CPUs. CHASSIS:(12/23/2014 02:23:01) Uncorrectable error detected for One of the DIMMs on Subsystem System Memory. The symptom can only be observed by the Three (3) DIMMs for One (1) CPU or Six (6) DIMMs for Two (2) CPUs ( One DIMM per channel ) configuration.
Resolving The Problem
Source
RETAIN tip: H213778
Symptom
System x3630M4/x3530M4 may report uncorrectable bus error on Central Processing Unit (CPU) and uncorrectable error on memory while performing excessive memory usage application or memory diagnostic.
The error from the Integrated Management Module (IMM) chassis event log is as follows and results in a system restart.
CHASSIS:(12/23/2014 02:23:11) An Uncorrectable Bus Error has occurred on bus CPUs. CHASSIS:(12/23/2014 02:23:01) Uncorrectable error detected for One of the DIMMs on Subsystem System Memory. |
The symptom can only be observed by the Three (3) DIMMs for One (1) CPU or Six (6) DIMMs for Two (2) CPUs ( One DIMM per channel ) configuration.
Affected configurations
The system may be any of the following IBM servers:
- System x3530 M4, type 7160 E5-xxxxV2, any model
- System x3630 M4, type 7158 E5-xxxxV2, any model
This tip is not software specific.
This tip is not option specific.
The following system BIOS/UEFI level(s) are affected: UEFI version 1.60/1.70/1.71 are affected.
Solution
The issue has been addressed by the UEFI firmware code version 2.12 or later.
The file is or will be available by selecting the appropriate Product Group, type of System, Product name, Product machine type, and operating system on IBM Support's Fix Central web page, at the following URL:
http://www.ibm.com/support/fixcentral/
Workaround
This issue can be worked around by changing the UEFI setting to lower memory speed from default 1600 MT/s to 1333 MT/s.
In UEFI setup menu, Select 'System Settings' --> 'Operating Modes' --> Choose Operating Mode: 'Custom Mode' --> Change Memory Speed to 'Balanced'.
Additional information
The system mistakenly triggers the failure symptom. The UEFI firmware will address this issue in next release.
Document Location
Worldwide
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Document Information
Modified date:
30 January 2019
UID
ibm1MIGR-5097080