The VDS_ SERVICE _NOTIFICATION structure provides information about state changes to the service object.<19>

 typedef struct _VDS_SERVICE_NOTIFICATION {
   ULONG ulEvent;
   VDS_RECOVER_ACTION action;
 } VDS_SERVICE_NOTIFICATION;

ulEvent: The type of service notification; it MUST be set to the following value.

Value	Meaning
VDS_NF_SERVICE_OUT_OF_SYNC 0x0000012D	The service's cache has become inconsistent or the service has encountered an error requiring client action.

action: The type of action required by the client to return the service to a functioning, consistent state; it MUST be one of the following values.

Value	Meaning
VDS_RA_UNKNOWN 0x00000000	The client corrective action is unknown.
VDS_RA_REFRESH 0x00000001	The client corrective action is to call the IVdsService::Refresh (section 3.4.5.2.4.10) method.
VDS_RA_RESTART 0x00000002	The client corrective action is to restart the service.