In the backup config panels, Windows Server Backup warns that with backup to a network share, the previous backups are overwritten. What I haven't figured out is whether a failed backup results in NO backup, or if the failed backup is just dropped, leaving the previous backup in-tact. In this scenario, the previous backup would be erased only after a successful subsequent backup.
Thanks!
Yes. Failed Backup results in NO backup.
You could try creating a .vhd file in your share location, attach it in disk management, then tell Windows Server Backup to use that as if it were a locally attached drive.