At 12:34 PM 5/28/98 -0400, you wrote:
>Has anyone upgraded an IBM 7331 ATL from regular 8mm drives to the ExaByte
>Mammoth drives?  Was the upgrade worth while?  How did you convert all of
>your old 8mm tapes over?
>
>
We converted one of our 4 7331-205 libraries to a 7331-305 (mammoth) drive
recently. The transition wasn't as smooth as we would have liked.

The original plan was to copy the existing tapes on the library to the
mammoth tapes gradually. However we ran into a major problem. There was a
defect on the drives which after you mounted and read a 7GB tape in the
drive, the drive would not mount 20GB tapes until you:

1. Cleaned the drive.
2. Reset the drive memory (press the eject button and hold for 10 seconds).
3. Power the drive off and on.

This was in March. IBM and Exabyte may have a microcode fix for this problem
(it was outlined in the IBM document TDR - H162792).

When I attempted to copy 7GB tapes off of the library using MOVE DATA,  the
read process appeared to be flaky, with numerous I/O errors.

To get around this problem, I interchanged SCSI addresses with a other
library (7331-205) and exchanged all the tapes between the two libraries. I
was then able to move the data off of the 7GB tapes to free space on other
libraries. The tapes and addresses were exchanged back and data was then
copied to the 20GB tapes. Because of space limitations, this process had to
be repeated 3 times.


In terms of "worth it", the upgrade effectively increases the the capacity
of the 7331 to about  2.5 times the original capacity of the 7331-205 (a
little less than advertised) and the upgrade price was about the same
(including media ($125 CDN a tape)) as what we paid for the original 7331-205.

By concentrating more data on a tape, it cuts down on the number of mounts
required to do a restore.

 -----------------------------------------------------------
   Don Coleman,
   Queen's University Information Technology Services
   Kingston, Ont. Canada  K7L 3N6
   Tel: (613) 545-2034   Email: Don.Coleman AT QueensU DOT CA