Mitch Collinsworth wrote:
>
> On Sat, 3 Aug 2002, Paul G. Allen wrote:
>
> > [root@ista root]# amtape csd show
> > amtape: scanning all 12 slots in tape-changer rack:
> > slot 2: reading label: Input/output error
> > slot 3: reading label: Input/output error
> > slot 4: reading label: Input/output error
> > slot 5: reading label: Input/output error
> > slot 6: reading label: Input/output error
> > slot 7: reading label: Input/output error
> > slot 8: reading label: Input/output error
> > slot 9: reading label: Input/output error
> > slot 10: reading label: Input/output error
> > slot 11: reading label: Input/output error
> > slot 0: reading label: Input/output error
>
> One common problem is that some changers will return from a tape
> load request before the tape is fully loaded and the tape drive is
> ready to go to work. In these cases it becomes necessary to add
> some delay time between the tape load command and subsequent tape
> drive use commands, or else do a sleep/retry/timeout sequence.
>
> Here's what worked for me a few years back with a DLT4000 changer:
>
> # see if tape drive is ready. if not, sleep a while and check again
> $remaining = $MAXDELAY;
> while (!open(TAPE,$TAPE) && $remaining > 0) {
> $remaining -= sleep 5;
> }
> if ($remaining <= 0) {
> print "$0 drive $TAPE timed out, not responding\n";
> exit 2;
> }
>
> I did this just after loading a tape, so any following commands would
> not have to worry about it. For that changer it took I think close to
> a minute for the drive to become ready.
>
> More recently, with an AIT2 changer I found the open() call here didn't
> work, so replaced it with a call to mt status and watched the output for
> "General status bits on".
>
I actually did have to add a delay, but in 2 places. I already had
delays in my script of 15 sec. after each load/unload, and a couple
seconds after arm movements, but I increased the longer delay to 20 sec.
That solved part of the problem, but I was still having issues with
rewinds and reads. Adding some debugging printf()'s in tapeio.c, I found
that the tapefd_open() function was failing. I added a longer delay in
there (changed from 2 to 3 sec.), and now it all seems to be working. I
was able to label all 12 tapes and then run "amtape csd show" with
success. amcheck -s also works now.
Now tomorrow I'll see about performing a test backup (I'm too beat now
after working on this all day).
PGA
--
Paul G. Allen
Owner, Sr. Engineer, Security Specialist
Random Logic/Dream Park
www.randomlogic.com
