An ESX Host gains exclusive access to Virtual Machines created on NFS datastores using which of th efollowing mechanisms?

A.
SCSI Reservations

B.
a special .lck-XXX lock file

C.
NFS File Locking Protocol

D.
Distributed File Locking

Explanation:
When your host accesses a virtual machine disk file on an NFS-based datastore, a .lck-XXX lock file is generated in the same directory where the disk file resides to prevent other hosts from accessing this virtual disk file. Do not remove the .lck-XXX lock file, because without it, the running virtual machine cannot access its virtual disk file.