I have had issues in the past with tape devices and the Windows Backup and Restore Utility (NTBackup.exe) where after a backup is complete, the NTBackup.exe process doesn't shut down and so it continues to tie up the tape drive. So you may have succesfully done a backup on one tape but when you insert another tape and try to read it, the system thinks the tape drive is still engaged reading or writing the previous tape.
Check out the Task Manager and see if you have an instance of the NTBackup.exe process running, even when you're not actually doing anything with the tape drive. If so, select the that process in Task Manager and kill it. Sometimes you can't kill the process in Task Manager so you may have to use something like the Kill utility or a tool like Process Explorer to kill it.
If all else fails and you can't kill NTBackup.exe, reboot the server and then after your server is back on line, insert your tape and try to read it. |