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	id PAA07269; Fri, 13 Jun 1997 15:54:40 +0100 (BST)
Subject: Re: dump/restore with compression
In-Reply-To: <Pine.NEB.3.95.970612185619.378B-100000@acp.qiv.com> from "Jay D. Nelson" at "Jun 12, 97 06:59:48 pm"
To: jdn@qiv.com (Jay D. Nelson)
Date: Fri, 13 Jun 1997 15:54:34 +0100 (BST)
Cc: brandon@ice.cold.org, lyndon@ve7tcp.ampr.org,
        freebsd-questions@freebsd.org
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> Use:
> 	dump 0uaf /dev/nrst0 /u1
> 	       ^
> ---------------|
> 
> That causes dump to write until EOT.
> 
> -- Jay
> 
> On Thu, 12 Jun 1997, Brandon Gillespie wrote:
> 
> ->On Thu, 12 Jun 1997, Lyndon Nerenberg wrote:
> ->> 
> ->> One option (it's a bit heavyweight I'll admit) is to install amanda
> ->> and use it to run the backups. It can compress the dump sets on the
> ->> way to the tape if you like.
> ->> 
> ->> In my case, I never compress backups. If you get a single I/O
> ->> error on a tape, you have almost no hope of retrieving any data
> ->> stored beyond the error. Uncompressed backups in dump format
> ->> can handle and recover from this. (Compression done in the tape
> ->> drive includes a *lot* of redundent information to help handle recovery
> ->> from bad media situations.)

Compress per file? (.gz.tar instead of .tar.gz) - or for small files, per
directory for a compromise between number of files per .gz and the amount
of compression. I don't know of anything that will do this though.

> ->> 
> ->
> ->Perhaps its how I'm executing dump, but when I run a tar of a filesystem,
> ->to tape, I can get the whole filesystem (without compression) but when I
> ->run dump, it asks for me to put in another tape without backing up the
> ->whole filesystem... I'm calling dump as:
> ->
> ->dump 0uf /dev/nrst0 /u1
> ->
> ->-Brandon Gillespie
> ->
>