A105@UWOCC1.BITNET (Brent Sterner) (11/11/86)
Thought I'd let the net know the problem was even worse than originally thought. The original tape was files-11 format at 6250 bpi. The 1st part of the tape was overwritten at 1600 bpi in BACKUP format. Why oh why is there no way to switch between the two without the tape rewinding? It took some effort, but in case it happens to you, here is how to get some of your data back. 1) Mount the tape with a ring. Use BACKUP to get as far into the tape as possible. The set the drive offline and open the door. Put a dummy load point reflective marker on the tape (look at a good tape to get it placed right). Then manually wind the reel past the new marker (several winds), and press the load button. 2) Wait a few seconds until VMS notices the drive is back again. At this point VMS should stop complaining about what you were doing to it's tape drive. 3) INIT the tape at the density of the rest of the tape (6250 in my case). Try to get back some files into a sub-directory using COPY. /LOG is recommended to follow what files get copied and where. This will in all likelihood fail with an ACP (? I think- too long ago now) error because the labels on the tape are out of synch with the s/w. 4) DUMP tape: This should be done on a CRT, since a lot of data might get dumped. Eventually this will terminate gracefully at the end of a file and display two consecutive EOF marks. 5) Go back to (3). Step 4 should synch the s/w with the tape, and the copy should then work. If not, iterate. In my case, the data came off after one DUMP pass. The main troubles I had were the density and format differences. I've received a lot of comments re preventing the problem which have not yet been fully digested. Many thanks to all who took the time to reply. When I get something together for my system, I'll broadcast again. Brent Sterner Computing & Communications Services Natural Sciences Building The University of Western Ontario London, Ontario, Canada N6A 5B7 Telephone (519)661-2151 x6036 Network <A105@UWOCC1.BITNET>