HP DLT/80 tar/dd backup I/O Errors

[Darin Perusich]

these tapes work for about a week for so in the new drive then they 
start to fail. have you tried using these tapes in a different drive? 
that could be a double edged sword, if the drive has a problem tapes 
used in that drive can pass those problems on to other drives.

it could also be the scsi bus it self. is there anything else on the bus 
that is throwing errors? i'm going to guess that you've checked the scsi 
id's and nothing is on id #7.

i've never heard of having to demagnetize a tape before using it. it's 
possible that the dlt is writting something to the first block of the 
tape and when you dump to the tape that block is getting written over 
and causing the problem. just a thought.

since you have a number of dlt's have you ever looked into using amanda 
to dump you systems? you can string all your dlt's together and make a 
virtual changer to increase capacity.

Justin Bennett wrote:
> Ok I just bought another HP DLT 40/80 GB Drive. This one I got a nice 4
> bay rack mount array for it and everything. I have two existing 40/80 DLT
> drives (diffrent model) that work great. However I just learned that any
> tape that was used in my old drives won't work in the new drive, unless I
> demagnetize them (from the manual of the drive) It was kicking my existing
> tapes out opon insertion. This is strange because I didn't think there was
> any type of formating on tapes, but there must be some kind of
> initilization on the tape.
>    Anyways thats not the issue, I bought a new set of tapes for this drive
> and everything was working fine for a few days.  Now I get Input output
> errors when writting to the tape. I use tar and dd to set the block
> size.
> 
> tar -cf /dev/st0 proj --blocking-factor 128
> 
> This is backing the proj directory. I get
> 
> Thu Sep 26 00:00:10 EDT 2002
> 
> Tape 0 Projects
> tar: /dev/st0: Wrote only 0 of 65536 bytes
> tar: Error is not recoverable: exiting now
> Thu Sep 26 01:23:37 EDT 20021
> 
> Sometimes it runs as few as 7 minutes in this case about an
> hour and a half. When I come in The clean/media light is blinking, I ran
> the cleaning cartridge several time, I still get the same thing the next
> night.
> 
> Any Ideas? Is an HP vs80 or something while the others are hp surestores,
> the surestores work just fine. They are all on the same SCSI bus, but the
> backups fire in sucsession, when one finishes the next goes, so I don't
> think it's a bandwidth issue on the bus. The files are on another server
> shared by nfs, on 100MBs FD switched network.
> 
> Justin


-- 
Darin Perusich
Unix Systems Administrator
Cognigen Corp.
darinper at cognigencorp.com