Troubleshooting Known Issues; Brown Out Conditions And The Ibm Bladecenter S Sas Raid Controller Module - IBM BladeCenter S SAS RAID Controller Module Installation And User Manual

13. Log into the Advanced Management Module and turn off the blue chassis
If the repair procedure did not resolve the problem, collect the logs and contact
IBM.

Troubleshooting known issues

This topic details some of the conditions that produce known issues for the IBM
BladeCenter S SAS RAID Controller Module.
Brown out conditions and the IBM BladeCenter S SAS RAID
Controller Module
Issue:
A "brownout" is a condition caused by a voltage level unexpectedly going below
the normal minimum level specified for the system. Systems supplied with
three-phase electric power also suffer brownouts if one or more phases are absent,
at reduced voltage, or incorrectly phased. Brownout conditions affect the RAID
Controllers and disk subsystem in a detrimental manner resulting in a an
Emergency Power Off Warning (EPOW) signal and a high probability of data loss.
If a brownout occurs, the power supply in the IBM BladeCenter S chassis triggers
an EPOW signal to storage system which causes it to suspend all host IO
operations and disk service communication despite the fact that this was not a
sustained loss of power. This prompts the Battery Backup Units go into service,
which moves the data to cache memory and places it in a persistent state. Once an
EPOW signal occurs, the set of actions it initiates must complete before you can
resume normal operations. This can take several minutes, and require multiple
system restarts.
The individual Blade servers react to the EPOW warning differently than the
storage system. In most cases, if power does not cease completely, a number of the
Blade servers might remain operational. However, because disk service
communication stops, the system can become unstable.
Recommendation
In configurations where outage due to brown outs are unacceptable, ensure your
system is protected with an Uninterrupted Power Supply (UPS) or other similar
solution.
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IBM SAS RAID Controller Module: Installation and User's Guide IBM BladeCenter S SAS RAID Controller Module
b. Close the release handle (rotate the handle up).
identification LED.
a. Log into the Advanced Management Module.
b. Click Monitors > LEDs > Media Tray and Rear Panel LEDs.
c. Click Off next to Location. The blue chassis identification LED will turn
off.