Subject: Re: Questions regarding dump
To: Current NetBSD users <firstname.lastname@example.org>
From: Greg A. Woods <email@example.com>
Date: 07/21/2000 09:48:20
[ On Friday, July 21, 2000 at 08:23:18 (+0200), Hauke Fath wrote: ]
> Subject: Re: Questions regarding dump
> At 22:20 Uhr +0200 20.7.2000, Manuel Bouyer wrote:
> >Actually I've found amanda to work quite well in my evironnemement (much
> >better than legato). When it'll can split a backup to several tapes, and
> >put more than one run on one tape I can't see any reason to use legato
> >(for me :)
> This is work in progress, afaik (Subject "Dumps across multiple tapes" on
> amada-hackers early this year), and may well be in Amanda 2.5.
No, unfortunately it's not yet in 2.5.0-current as of 2000/07/03.
The first draft design for allowing dump images to span multiple tapes
(in docs/MULTITAPE) claims to have been written 3/29/94, so I'm not
holding my breath... (any more! ;-). One tricky part not discussed in
that document is the issue dealing with splitting an archive. The
current design doesn't take into account the details of doing this
properly in a reliable manner. For dump-format archives the trick is
fooling restore into seeing the Nth volume. Splitting tar and cpio
archives properly so that no file is split across tapes is still a bit
more involved than the current design admits, but it's still possible.
Amanda does work very well. I've used it off and on since about 1994,
but I must say that it works especially well with a tape changer robot.
I've had 2.4.1p1 running with an EXB-10H and an EXB-8505 tape, basicaly
unattended (except for tape change outs and manual cleanings) at one
customer site since April 1999. I have a EXB-210 library and EXB-820
tape at home too, and without Amanda and the library I would never be
doing regular backups at home!
I use dump, of course, as the underlying backup mechanism. If your
library will hold enough tapes such that you have at least two full sets
of level-0 dumps then even tape management with Amanda is trivial.
Some of Amanda's code internally is the worst looking crap I've seen
since hacking BASIC code in high-school and is, at least IMO, badly
designed in places, but it is constantly being improved, both in design
and implementation, and it does work a *lot* more reliably than doing
I should note too that I've never used any of the commercial backup
tools, at least not since performing destruction rituals on a copy of
that most horrid BRU software about a dozen years ago! ;-)
Greg A. Woods
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