Re: tar incremental backups confusion
From: Stuart McGraw (smcg4191_at_frii.RemoveThisToReply.com)
Date: Mon, 9 Feb 2004 10:13:42 -0700
Thanks, Alan. I am looking into that. But my puzzelment
is that the doc and a zillion usenet posting all say that -g
is good and should be used, but as fas as I can tell, it is
inferior the the "old" -G option, at least when it comes to
a bare metal restore. I would like to think that a zillion
people and the docs are wrong, and I am right, but...
So I am still hoping for a more comprehensive explanation.
Maybe linux users never have to do bare metal restores?
Or maybe those that have are now using something other
"alan" <firstname.lastname@example.org> wrote in message news:email@example.com...
> firstname.lastname@example.org (smcgraw) wrote in message news:<email@example.com>...
> > I am trying to understand how to use GNU tar's --listed-incremental
> > (aka -g) option, and am getting very confused.
> > If I use the -g option on an incremental backup and I then
> > later want to do a restore without getting any extra previously
> > deleted files, I need to give tar the -g option with the same
> > snapshot file that the original incremental backup created,
> > yes?
> > But if my disk was wiped that file is gone! Since it is (I
> > think) created after the incremental backup, I can't include it
> > in the tar file, I have to write a second tar file to backup
> > the incremental's snapshot file? (Or append, or update the
> > incremental tar file?) I looked at a few backup scripts found
> > on the net and none seem to do this. Why not?
> > Now if I need to restore, I have to read past the incremental
> > tar file on the tape, restore the snapshot file, move back over
> > the incremental tar file, then do the incremental restore? This
> > is pretty cumbersome, isn't it?
> > The -G (--incremental) option will write a snapshot file as
> > part of the tar file. So no other file is needed at restore time?
> > Does it make sense to use both -g and -G on a backup? If so
> > why does the manual say that -g has superceeded -G and -G is not
> > recommended?
> > I am very confused....
> > What is best way to do an incremental backup that can be restored
> > using *only* the data on the tapes?
> you probably need to investigate the --newer-mtime option instead.