My destination directory is on a drobo. I experienced some power outages and the drive was going very slow for all file access. I was going to do a chkdsk and after 10 days it had only completes 60%. So I formatted the drobo. Now my file access speed is much better. It is in the process of performing backups now but do I need to do anything to tell the server that the old backup data is no longer present or will the server figure it out.