Systems or components may lose power after the system has been up for a long time. Power cords work their way loose if they are not plugged into the power supply or the PDU, also known as a power strip.
The system will report the power failure in /var/log/messages as
2021-09-02T16:00:01-05:00 s-sa disk_subsystem: snlog: sn="00:d0:83:10:30:b2" id="DS" m="23" c="6" event="DISK_STATUS" category="HARDWARE" ip="126.96.36.199" model="S500" msg="Adapter 2; seqNum: 0x00025b06; Time: Thu Sep 2 21:18:46 2021; Event Description: Enclosure PD 0f(c Port 4 - 7/p1) Power supply 1 switched off; Device ID: 15; Enclosure Index: 1; Slot Number: 1; "
The pink banner may indicate that there is a hard disk problem. This is incorrect but it will at least let you know something needs your attention.
The power source may become disconnected.
This will happen on all releases of the software and on directly attached hardware. Storage such as NetApp or Dell MD3860 will receive errors through the MDSM or SANtricity client.
The fault on the drive enclosures can be found by running a megacli command. Run megacli -encinfo -A1 for adapter 1, or -A2 as needed for adapter 2 and look at the values for "Voltage Sensor Status". These should be "OK." If they are not OK and are Critical, then there is power missing from one of the power supplies.
For the J5300 enclosures, if Voltage Sensor 9 and Voltage Sensor 10 are Critical, check the left power supply as seen from the back of the enclosure. If Voltage Sensor 12 and Voltage Sensor 13 are Critical, check the right power supply as seen from the back of the enclosure.
Physically check the hardware in the data center. There should be two green lights to the left of the power switch for each of the power supplies. If they are not on, there is a problem. In this case, the power supply to the left is turned off and the two green lights are off.
For the Dell MD1400 drive enclosures, the lights are in the top left or top right corners, above the power cords. The top left in this case has no power while the top right lights show there is full power. The power cord on the left is not in tight. If the bottom light is on, the power cord is plugged in but the power switch is off. The power status would need to be checked from the iDRAC.
Check the power cords and push them in hard. Check that the power switches are all on.