[root@localhost testing]# mt -f /dev/st0 rewind
[root@localhost testing]# mt -f /dev/st0 rewind
[root@localhost testing]# tar -tzf /dev/st0
backup.err
backup.smsjet.com.err
backup.smsjet.com.pid

[root@localhost testing]# mt -f /dev/st0 rewind
[root@localhost testing]# tar -xvf /dev/st0 backup.err
tar: This does not look like a tar archive
tar: Skipping to next header
tar: Archive contains obsolescent base-64 headers
tar: Archive contains `!\235\263\023\235q\240\357\232\004\034Y' where numeric off_t value expected
tar: Skipping to next header
tar: backup.err: Not found in archive
tar: Error exit delayed from previous errors
[root@localhost testing]#