Our PS team upgraded some NetWitness decoders that are connected to Unity from 126.96.36.199 to 11.5.2 and CentOS kernel also updated as part of this upgrade activity. After then, they were not able to mount Unity SAN filesystem due to a conflict of the existing multipath. The issue was resolved by disabling multipath and system reboot first time. But the issue happened again with the "kernel panic" error from /var/log/messages and "A runtime critical stop occurred" error from iDRAC console log.
These are observations in the customer environment.
PowerPath service loaded SAN storage volumes using pseudo name (emcpowerb, emcpowerc)
Saved the PowerPath configuration
Confirmed multipath driver has not been loaded (multipath -ll).
Tried to mount the volumes by issuing command
Right after the mount command above, Kernel panic happened again.
Customers were using CentOS 7.8.2003 with PowerPath version 6.4 at that time.
The current version of PowerPath for Linux is Not supported with CentOS [x86_64] 7.8 and its Kernel Version 3.10.0-1127.18.2.el7. The Only version of PowerPath for Linux which is certified and is supported with CentOS [x86_64] 7.8 and its Kernel Version 3.10.0-1127.18.2.el7 is PowerPath for Linux version 7.2 Recommend upgrading PowerPath ASAP. This very much could be the reason for the kernel panics.