June 21, 2013
NOTICE:
THIS FIELD NOTICE IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF THE INFORMATION ON THE FIELD NOTICE OR MATERIALS LINKED FROM THE FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME.
Revision History
Revision Date Comment
Products Affected
Products Affected
Problem Description
A voltage regulator on affected UCS B-Series Blade Servers can cause excessive loss in drive voltage on the DDR3 power rails when under light loading conditions. This can cause correctable or uncorrectable memory errors. A firmware update is recommended to improve the performance of the voltage regulator.
Background
A firmware setting for a voltage regulator on affected UCS B-Series Blade Servers can cause signal corruption which can lead to memory errors and failure to boot in some cases. This issue has been observed in the Cisco manufacturing facility as a failure to boot Linux OS. The problem is fixed in an updated firmware image for affected UCS Blade Servers. These Cisco bug IDs are related to this issue:
- CSCug93076 - B200M3-DDR voltage regulator may have excessive noise under light load
- CSCug93221 - B420M3-DDR voltage regulator may have excessive noise under light load
- CSCug98662 - B22M3-DDR voltage regulator may have excessive noise under light load
Problem Symptoms
Memory errors caused by the excessive voltage drop could show up in these ways:
- Increased correctable memory error rates might cause DIMMs to be mapped out at boot time or be flagged as Degraded or Inoperable.
- Uncorrectable memory errors might cause DIMMs to be mapped out at boot time, or might cause the system to crash while the operating system boots or runs. A system crash is accompanied by a catastrophic error (CATERR) in the System Event Log (SEL).
Example:
Key word to search for: "Predictive Failure asserted | Asserted" often followed immediately by "Predictive Failure deasserted | Asserted"
91 | 05/31/2013 10:39:36 | CIMC | Processor CATERR_N #0x74 | Predictive Failure asserted | Asserted
92 | 05/31/2013 10:39:36 | CIMC | Platform alert LED_BLADE_STATUS #0x99 | LED color is amber | Asserted
93 | 05/31/2013 10:39:37 | CIMC | Processor CATERR_N #0x74 | Predictive Failure deasserted | Asserted
94 | 05/31/2013 10:39:37 | CIMC | Platform alert LED_BLADE_STATUS #0x99 | LED color is green | AssertedInstructions on how to retrieve SEL information can be found here:
Workaround/Solution
The issue is resolved in these Cisco UCS B-Series software releases:
- UCS B-Series Software Release 2.0(5c) or later
- UCS B-Series Software Release 2.1(1f) or later
Note: A host power off and a Cisco Integrated Management Controller (CIMC) reboot is required for this fix to take effect. This is NOT a normal upgrade sequence. Please carefully read and follow the steps documented in the release note.
UCS software can be downloaded from Cisco.com from this location: Download Software
UCS software upgrade instructions can be found at this location: UCS Install and Upgrade Guides
How To Identify Hardware Levels
Some UCS B-Series M3 Blade Servers have shipped from Cisco with updated voltage regulator firmware and an older software version than those noted in the Workaround/Solution section. These Blade Servers can be identified by a deviation sticker affixed near the front of the unit. These Deviations apply for the issue described in this Field Notice:
- B200 M3: D135723
- B22 M3: D136090
- B420 M3: D135856
Deviation Label examples:
A UCS B-Series M3 Blade Server with the versions noted in the Workaround/Solution section have the required fix for the issue described in this Field Notice.
In order to view the version installed on the UCS Blade Server in UCS Manager, navigate to this location for each blade:
Example:
UCSM > Chassis > Servers > Server > Installed Firmware
For More Information
If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:
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