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.
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
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.
# /opt/MegaRAID/MegaCli/MegaCli64 -AdpBbuCmd –a0 > /tmp/BBUDetails.txt
# /opt/MegaRAID/MegaCli/MegaCli64 -AdpBbuCmd -BbuLearn –a0
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.
This issue affects NetBackup 50x0 (all versions) and 52x0 (versions through 2.5.2) Appliances.