Re: xfsdump/xfsrestore question

Olaf Frączyk
2007-02-22T13:02:18Z

On Wed, 2007-02-21 at 11:07 +1100, Timothy Shimmin wrote:
> Hi,
>
> --On 20 February 2007 4:16:31 PM +0200 Leon Kolchinsky <leonk@construct.haifa.ac.il> wrote:
>
> > Hello All,
> >
> > I have a question about xfsdump/xfsrestore usage on Linux.
> >
> > Now the questions:
> >
> > 1) If I get the xfsdump synax correctly I just have to do:
> >
> ># cd /
> ># xfsdump -f /data/backup.file /
> >
> > Is it right?
> > What about opened and "currently in use by the system" files? Are they
> > backuped in a proper way? What about tmpfs like /proc, are they been
> > ignored?
> >
(...)
> Yes it is meant to handle a changing filesystem - you do see warning msgs sometimes because
> it can't see a particular inode anymore, which can happen as we do multiple
> scans of the inodes and if they get deleted then it obviously can't do anything
> with it anymore or if the inode is reused as a dir instead of a reg-file etc...
Hmm,
I suppose he asked about something else:
Unless you use lvm snapshots (or something alike) you may get incorrect
files that are in use. Consider having 20GB file:
1. Dump starts reading the file
2. Dump is at 18th GB
3. You change the data in 1-5 GB region.
4. You have inconsistent data.

So after dump you get consistent filesystem but not necessairly
consistent data.

Regards,

Olaf

--
Olaf Frączyk <olaf@cbk.poznan.pl>