Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!cbmvax!grr
From: grr@cbmvax.commodore.com (George Robbins)
Newsgroups: comp.unix.ultrix
Subject: Re: Multiple dump files per 8mm tape
Message-ID: <13221@cbmvax.commodore.com>
Date: 16 Jul 90 00:34:32 GMT
References: <71@thoreau.nsc.com> <13219@cbmvax.commodore.com>
Reply-To: grr@cbmvax.commodore.com (George Robbins)
Organization: Commodore, West Chester, PA
Lines: 26

In article <13219@cbmvax.commodore.com> grr@cbmvax.commodore.com (George Robbins) writes:
> In article <71@thoreau.nsc.com> macomber@thoreau.nsc.com (Robert Macomber) writes:
> > I hate to parade out this tired out old question...
> 
>...                   I'm beginning to suspect either backup or restore is
>making wrong assumptions about tape block size for the second file on a
> ulti-file tape.  ("low density" uses a smaller block size than "high density")

Oh, well...never mind...

What is, is that that 4.3BSD dump that I used to use before switching to this
RISC stuff is clever enough to increase the block size when writing to a
"high density" media.  The Ultrix version isn't clever enough to do this and
always writes itsy-bitsy 10240 byte blocks. 

My daily incremental dump script was still specifying -b 32, which is a no-op
with the BSD dump, but which does override the dump blocksize on the Ultrix
dump and thus creates tape images that the Ultrix restore can't read in.

I'd really appreciate it if anyone that has diffs to the 4.3 Tahoe dump/restore
to make it work under Ultrix would post them or mail them here...

-- 
George Robbins - now working for,     uucp:   {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing:   domain: grr@cbmvax.commodore.com
Commodore, Engineering Department     phone:  215-431-9349 (only by moonlite)