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Appliance RAID battery showing incorrect readings before or after replacement

Article: 100029051
Last Published: 2014-02-18
Ratings: 1 0
Product(s): Appliances

Problem

The BBU (Battery Backup Unit) is indicating the battery needs to be replaced; however, the absolute state of charge is good and the RAID volume’s write cache is still enabled.  This isn't an actual BBU failure.  Instead, the reported status is incorrect.

Error Message

Receiving Hardware Monitor Event emails and/or callhome telemetry data shows a failed BBU:

BBU status for Adapter: 0
Battery Replacement required : Yes
Relative State of Charge: 98 %
Charger System State: 49168
Charger System Ctrl: 0
Charging current: 0 mA
Absolute state of charge: 96 %
Max Error: 2 %
 
Default Cache Policy: WriteBack, ReadAdaptive, Direct, No Write Cache if Bad BBU
Current Cache Policy: WriteBack, ReadAdaptive, Direct, No Write Cache if Bad BBU

Solution

In this situation, the message saying that the battery needs to be replaced is a false indication as the Relative and Absolute State of Charge show normal healthy levels. In addition, the write cache is still enabled so no performance impact should be noticed.

After a battery is replaced, within 24 hours it should complete an automatic relearn. If the battery relearn has not initiated,  it is recommened to start this process manually.
 
If at all possible add the battery details, specifically the date of manufacturer and PCB revision level, to the case. Use this command:
# /opt/MegaRAID/MegaCli/MegaCli64 -AdpBbuCmd –a0 > /tmp/BBUDetails.txt
 
Then recalibrate the battery by kicking off a manual relearn:
# /opt/MegaRAID/MegaCli/MegaCli64 -AdpBbuCmd -BbuLearn –a0
 
The relearn should recalibrate the battery and correct the warning. Should the relearn not resolve this or if the command fails, then the case should be escalated for futher analysis.

Note: In NetBackup Appliances 2.5.3, Hardware Monitoring events will no longer be sent given the indication above as this is a false failure. To take advantage of the new BBU monitoring logic, upgrade to 2.5.3 or above or request and apply one of the EEBs listed below based on the customer release version:

  • 2.0.3 Release EEB 3206566
  • 2.5 Release EEB 3234901
  • 2.5.1 Release EEB 3231016
  • 2.5.2 Release EEB 3200495

For NetBackup PureDisk 5000/5020 Appliances 1.4.4, a fix is included in the EEB bundle attached to the Related Article linked below.  Download and apply this bundle.

 

Applies To

This issue affects NetBackup 50x0 (all versions) and 52x0 (versions through 2.5.2) Appliances.

References

Etrack : 3198837

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