Subject: Re: Amanda backups: gtar or dump?
To: Simon J. Gerraty <>
From: dustin sallings <>
List: current-users
Date: 10/25/1998 14:48:04
On Mon, 26 Oct 1998, Simon J. Gerraty wrote:

// I've just finished setting up amanda here (been on my todo list for
// over a year :-) and am trying to decide whether I should use dump or
// gnu tar and would appreciate opinions of others.

	I would always prefer dump over tar.

// I've mainly used dump in the past as it was much quicker than my
// perl/cpio backup stuff.  I suspect that dump will also be quicker
// than gnu tar (just from watching gnu tar last night "estimating" how
// big backups were going to be), but I know dump is a tad risky on
// live filesystems.

	I've not had a problem yet.

// I do have non-netbsd systems here, but all support dump, and most
// contain only their OS.

	My backup machine is SunOS 4.1.4.  It backs up itself, a NetBSD
1.3.2 i386 box, a NetBSD 1.3.2 hp300 box, an OpenBSD/sparc box, and it
used to do my SGI, 'til my SGI started doing weird things.

// I also noted that the example disklist shows a prefernce for
// compressing dumps - but my DAT (Seagate/Archive python) drive does
// compression so I assume its better to let the tape drive do it? Just
// letting the drive do compression would certainly help amanda with
// its tape space estimates.

	There was something in the FAQ about that, but I forgot what.  It
seems like it was a no, don't use the hardware compression because we
don't know when we're going to run out of tape.  I use client side
compression everywhere 'cept the backup server, and where I'm doing
highly compressed data.

// Also, I was a bit reluctant to re-enable rsh on my systems - even
// though it is blocked at the ppp link.  Has anyone hacked amanda to
// use ssh?  Otherwise I might just munge it to use ssl_rcmd().

	It doesn't use rsh exactly, just uses the same kinda permissions.
You can make it use .amandahosts instead of .rhosts if you want.  Ssh
won't exactly work because the estimates go over UDP.  You could probably
do something with photuris, but that's leaning way towards unportable.

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