Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uunet!ogicse!cvedc!mcspdx!adpplz!martin
From: martin@adpplz.UUCP (Martin Golding)
Newsgroups: comp.unix.questions
Subject: Can't cat tape- big blocks?
Message-ID: <803@adpplz.UUCP>
Date: 13 Jun 91 21:54:58 GMT
Article-I.D.: adpplz.803
Distribution: usa
Organization: ADP Dealer Services R&D, Portland, OR
Lines: 28

We're using unix V3.2 ,more or less, Motorola's release 2 on 88k's

We got a 9 track tape in tar format, with 10k blocks. It's from a BSD type 
system (at least, the tar headers match my sun manuals and tar from
the Motorola doesn't work). The only tape drive we have is on one of
the Motorola boxes, so what we figured was, we'd cat it to a file
on the Motorola box and then rcp or rsh tar the puppy from the Sun.

When we cat it to a file (cat /dev/r50t >/dir/bigfile), it looks
like we don't get all the data from the tape. We get the same effect
if we rsh cat <the device>.

My hypothesis is, we're using the wrong driver (either it doesn't buffer
internally, or the buffers it has are too small) or all the drivers have
too small internal buffers. 


What should we do? All suggestions appreciated, interesting experiments
cheefully undertaken.

Please help, the tape is from some furiners, and it could take us weeks
to get another.


Martin Golding    | sync, sync, sync, sank ... sunk:
Dod #0236         |  He who steals my code steals trash.
A poor old decrepit Pick programmer. Sympathize at:
{mcspdx,pdxgate}!adpplz!martin or martin@adpplz.uucp