CFBMC-965: False-positive NVMEM battery alerts sometimes cause ONTAP to shutdown during an active learning cycle on some systems
Issue
- On some storage systems, the learning cycle feature of the nonvolatile memory (NVMEM) battery interrupts some of the readings from battery sensors during an active learning cycle.
- Sensor readings that drop below threshold values can trigger false-positive alerts and might cause ONTAP to shut down.
- The following models are potentially affected:
- AFF A800, AFF A700, AFF A320, AFF A220, AFF A200, AFF C190
- FAS9000, FAS8200, FAS2750, FAS2720, FAS2650, FAS2620
- You might see the following error messages when this issue occurs:
To prevent data loss, the system will shut down in 20 minutes.
.. 01:04:34 [node02:nvmem.battery.capLowCrit:EMERGENCY]: The NVMEM battery capacity is critically low (0 cycles).To prevent data loss, the system will shut down in 20 minutes.
.. 01:04:53 [node01:callhome.battery.failure:EMERGENCY]: Call home for BATTERY (full charge capacity low) CRITICAL. .. 01:05:03 [node01:callhome.battery.failure:EMERGENCY]: Call home for BATTERY (capacity low) CRITICAL. .. 01:23:54 [node01:monitor.shutdown.emergency:EMERGENCY]: Emergency shutdown: Environmental Reason Shutdown (Battery PCT capacity critical) .. 01:33:39 [node1:nvmem.battery.capNormal:notice]: The NVMEM battery capacity is normal.- The false positive alert message is sometimes followed by a "return to normal" message. The battery learning cycle occurs every 70 days and takes approximately 19 hours to complete. During this time, the system is susceptible to this issue.