Re: [ILUG] Linux Backup options

From: Conor Daly (conor.daly at domain oceanfree.net)
Date: Tue 16 Apr 2002 - 10:30:07 IST


On Wed, Apr 10, 2002 at 03:42:59PM +0100 or so it is rumoured hereabouts,
Brendan Halpin thought:
> Nick Murtagh <murtaghn at domain tcd.ie> writes:
>
> > On Wednesday 10 April 2002 15:00, Brendan wrote:
> > > I'm interested in the recent suggestion that differential backups
> > > are better than incremental: i.e. after first run, do daily backups
> > > of all changed since first run, not since last run. Any ideas how
> > > to accomplish this with this setup?
> >
> > One way is to use the --newer option to tar. You have to store the date of
> > the last full backup, and then every incremental one should pick up files
> > that have changed since then. I don't think you can do this as I've described
> > with a tar one-liner though...
>
> tar --file Tuesday.tar.gz --newer `clever-command Monday.tar.gz`???
>
> Is there a good way of achieving that? ie extract the creation date
> of the first-run archive.
>
> What I'd be happier with would be a way of reading the .snar file
> created by the first-run, without updating it...

You mean like

cp /backup/home.snar.full /backup/home.snar
tar --create \
    --gzip \
    --file=/backup/incr/home_`date "+%Y%m%d%H%M%S"`.tar.gz \
    --label="`hostname` /home `date +%Y-%m-%d`" \
    --listed-incremental=/backup/home.snar \
    --exclude="/home/brendan/ftp_temp/*" \
    /home/;

or does that defeat the "only use tar" idea?

Conor

-- 
Conor Daly <conor.daly at domain oceanfree.net>
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