Availability of Services While Restoring a
vCenter Server
Instance

During the process of restoring the
vCenter Server
backup file, services in the
vCenter Server
instance must restart. While they are restarting, your API client receives an error message.
You can write your client to trap the error, but you have no way to know when the
vCenter Server
services are running again. To determine when the restore process is complete, you must retry the API connection until it succeeds, then request the status of the job.