Re: dump problems

On Mon, 10 Sep 2007 14:14:00 +0200 Markus Hitter <mah_at_jump-ing.de> wrote:
> Am 10.09.2007 um 10:14 schrieb Danny Braniss:
> > so here are some questions:
> > 	- is the readers/writer split realy needed now? my guess it was
> >           put in in the old days to get tapes streaming - which is  
> > btw,
> >           what's not working.
> Before you put a lot of efforts into this: Why don't you just let  
> dump/restore die and put functionality, which is needed and unique to  
> dump, into tar?

Because doing that would require rewriting tar pretty much from the
ground up?

> Tar is far more popular, today's world is multiplatform, today's
> world is multi-filesystem and if you rewrite dump, you force admins
> to rewrite their scripts anyways.

Tar is an excellent tool for moving data between platforms and file
systems. It's not a good tool for backing up a file system. Fixing
dump won't necessarily require admins to fix their scripts - it's been
done more than once in the past.

> I've always considered it as sub-optimal to have several tools for  
> one task.

Just because multiple tools can perform task doesn't mean you have
multiple tools for that task. I.e. - you can convince cat, cp, tar,
sed, awk, rsync, and a host of others can copy a file. Which one you
use depends on what you're trying to do.

There's only one tool that can be used to reliably back up and restore
a file system - and that's dump. Tar, cpio, GNU cp, etc. can be used
to do the job, but they don't always get it right. In particular, none
of them will correctly reproduce holes in files. dump will. Symlinks,
special files, and similar things all cause some of the others to do
odd things - exactly which ones and exactly what odd things varying
depending on what you're looking at and the version of the other
thing.

	<mike
-- 
Mike Meyer <mwm_at_mired.org>		http://www.mired.org/consulting.html
Independent Network/Unix/Perforce consultant, email for more information.