In <H00010c21090a4d4@MHS> [log in to unmask] writes:

> Item Subject: DDS3 Problems
> It seems like when you replaced the replacement drive, the tapes were readable
> e?

No. New tape drive can also not read the bad tapes produced by the previous
one. We still have a (growing) stack of useless backups tapes.

> I've recently become aware of some possible problems with certain batches of D
> DDS
> tapes.  I do not have specifics as the problem is of course hard to isolate bu
> ut
> you might be able to provide HP some data here. You may want to examine your
> tapes for the date codes to see if they were from the same lot(s).  Also, the
> shape of the tape viewing window (Oval or Rodent ears[like a mickey mouse hat]
> ]),
> color of the printing, etc. may be used to identify different suppliers to HP
> (assuming you are using HP tapes).

We are also checking into this as one of the HPRC engineers brought this up,
however other tapes from the same "batch" were used successfully on our Sun
Enterprise servers without problems...

> Also, since your problems, I'm going to try to develop a process to extract
> the info from the LOG records of the tape closure info that will expose
> the number of Read After Write and ECC errors per number of blocks written at
> the time of our backups.  Perhaps, this can flag a failing tape drive or
> at least a marginal tape.  This will use LOGTOOL and a script I think.
> If you would be interested, I'll send you my results (when and if) they are
> ready.

Would be very interested.

> Finally, the tape support web pages say that a tape is initialized only
> once (the first time inserted into a drive after being unwrapped), so if
> a tape was first used in a "marginal" drive, the tape may remain marginal
> forever.  Best to trash any suspect tapes.  Not cheap but neither is data loss
> s!.

Interesting! Didn't know that...

> Final, Finally, the support pages harp on treatment of the tapes - be gentle,
> keep in the cases, the area must be very clean and humidity seems to critical
> (40 to 55% relative humidity is strongly suggested), store in an upright
> position, and on and on....   especially important is that a dirty tape
> (even a dirty cleaner tape) can propagate problems from drive to drive....
> scary stuff.  I guess that just because we're paranoid doesn't mean They
> aren't out to get us!

We're very careful with the drives and media. They generally never leave the
(locked/controlled) computer room, except to go to offsite storage. All the
tapes we've had problems with never left the computer room.

> Sounds like you got your data back, that's the best news,

Nope... unfortunately.

> James (older, wiser, and now more questioning of backups) Overman

Us too. Getting quotes on DLT7000 systems as I type.

      -Chris Bartram