Ask the storage backend to refresh the fields in the VDI object

Parameters
name	type	description
session_id	session	valid session reference
vdi	VDI	The VDI whose stats (eg size) should be updated
Errors
name	arguments	description
SR_OPERATION_NOT_SUPPORTED	sr	The SR backend does not support the operation (check the SR's allowed operations)

• Message has both a synchronous and asynchronous version
• This is a custom message