A VMFS datastore holds virtual machine files, directories, symbolic links, RDM descriptor files, and so on. The datastore also maintains a consistent view of all the mapping information for these objects. This mapping information is called metadata.

Metadata is updated each time the attributes of a virtual machine file are accessed or modified when, for example, you perform one of the following operations:

Creating, growing, or locking a virtual machine file

Changing a file's attributes

Powering a virtual machine on or off