Manual removal of the datastore through the vSphere Client.
:
Unmount first:
For advanced recovery, you might need to use command-line tools.
If the datastore does not automatically reappear: recover vmfs datastore esxi 5
If the ESXi host sees the disk but not the datastore, the partition table may be missing. You can often rebuild it manually using the ESXi command line.
partedUtil get /dev/disks/naa.YOUR_DISK_ID Manual removal of the datastore through the vSphere Client
If the datastore still doesn’t appear, you might need to use the ESXi command line.
VMFS5 on ESXi 5 has known bugs with dirty shutdowns. The safest recovery is: recover vmfs datastore esxi 5