The below log line started to appear in the Event logs which states one of the disk is not working.
2022-04-25T00:50:02.525610+00:00 CD2MAA-LSEPX04 alert hm.notification[17319]:Health monitoring: PROBLEM - CD2MAA-LSEPX04 Metric: RAID casma-raid Working Members WARNING - 5/6 members are working
If you notice this or similar errors, it means disk is faulty. RMA for HDD needs to be processed.