Re: dump on ext3

["Jim C. Brown" <jbrown106@phreaker.net>]

On Thu, Jan 06, 2005 at 04:13:16PM -0500, Kirkwood, David A wrote:
> Does dump work reliably on an ext3 filesystem?
> 
> Here's the senario:
> 
> I have a raid 5 linux system ( RH 7.3 ). I currently backup the system to
> tape in case of catastrophic failure. I am up to multitape backups for full
> user partitions.I want to use incremental dumps and spread my full system
> dumps further apart, but tme man page says dump can be used for ext2. There
> is no mention of ext3 one way or the other. Assuming 1 tape drive, the need
> to do backups unattended, the inability to shut the system down  
> everttime I need to dump files, I need to use dump unless someone has a
> better solution. New backup h/w etc in not an option as i have already
> submitted need for tape library etc and its working its way through the
> corporate higharchy but it may be 6 month untill I see something.
> 
> As always, all input is appreciated.
> 
> Dave

I'm not 100% certain of this, but it should work. File system wise, ext3
is just ext2 with a journal inode (which looks like a regular ext2 file).

I suppose it is possible that dump might have a problem with the journal inode
on a mounted ext3 system, but even if that is the case it should be easy to work
around, as it seems Dump 0.4b36 from http://sourceforge.net/projects/dump/
supports ext3 (all versions do, but that's the only one called ext2/ext3 dump).

You might also be interested to read this, from
http://nslug.ns.ca/pipermail/nslug/2003-November/005980.html

> Changes between versions 0.4b9 and 0.4b10 (released November 21, 1999)
> ======================================================================
> ...
> 4.      Integrate a patch from Jeremy Fitzhardinge <jeremy at goop.org>
>         which allows dump on an active ext3 filesystem. However, this
>         is a "quick and dirty" patch which enables backup of an ext3
>         filesystem through the ext2 compatibility (by ignoring the
>         NEEDS_RECOVERY bit). The journal file is not recognized and
>         it is dumped (it should not).
>
>
> Unless I have missed something, nobody ever saw a need to improve on the
> "quick and dirty" patch (or at least there is no subsequent mention of ext3
> in the changelog) so it should be possible with a modern 'dump' to dump ext3
> and get exactly the same results as if the filesystem had been ext2, just as
> it says above.
>

-- 
Infinite complexity begets infinite beauty.
Infinite precision begets infinite perfection.