CONTAP-66718: False-positive NVMEM battery alerts might cause ONTAP to shutdown during an active learning cycle
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 events are an example of this issue: 20:00:46 [node1: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. 20:01:46 [node1:callhome.battery.failure:EMERGENCY]: Call home for BATTERY (capacity low) CRITICAL. 20:02:36 [node1:nvmem.battery.fccLowCrit:EMERGENCY]: The NVMEM battery full-charge capacity is critically low (25 %). To prevent data loss, the system will shut down in 20 minutes. 20:03:36 [node1:callhome.battery.failure:EMERGENCY]: Call home for BATTERY (full charge capacity low) CRITICAL. 20:22:36 [node1:monitor.shutdown.emergency:EMERGENCY]: Emergency shutdown: Environmental Reason Check the BMC's system event log (SEL) to confirm a battery learning cycle was active at the time these event were logged.