Recover Vmfs Datastore [best] -

Before blaming VMware, look at the storage array.

If the storage array shows the LUN is presented, but ESXi doesn't see it, proceed to the ESXi command line. recover vmfs datastore

esxcli storage filesystem list

First, list the file system volumes to see if the system detects the VMFS filesystem but hasn't mounted it: Before blaming VMware, look at the storage array