This monitor tracks the vCenter Alarm 'Errors occurred on the disk(s) of a Virtual SAN host'.
By default, the alarm is triggered by the following event:
|▪||esx.problem.vob.vsan.lsom.diskerror: Virtual SAN device encountered a permanent error when devices were not readable or writeable.|
For more information on the issue, see this VMware KB article.
This alarm doesnot resolve be default; go to the vSphere Client and clear the alarm manually.
See the VMware Online Documentation for more information on VMware vSphere, in particular: