[CentOS] Antwort: Re: du vs df size difference

Thu Oct 1 17:42:30 UTC 2009
Frank.Brodbeck at klingel.de <Frank.Brodbeck at klingel.de>

Robert Heller <heller at deepsoft.com> schrieb am 01.10.2009 19:35:20:
> At Thu, 01 Oct 2009 10:13:26 -0400 CentOS mailing list 
> <centos at centos.org> wrote:
> 
> > 
> > Peter Kjellstrom wrote:
> > > One possibility is that the missing data is hiding under a 
> mount-point in the 
> > > normal case.
> > > 
> > > /Peter
> > 
> > So what you're saying is something is mounted on to a directory that 
had 
> > data in it before the mount.  How do I see the data being hidden 
without 
> > unmounting the point?
> 
> You can't.  You must unmount.  You should be able to do this from
> single user mode if the file system cannot be unmounted under multiuser
> mode (eg /usr, /var, etc.).  Usually other mount points can be
> unmounted, but depends on what is running on the system at the time. 
> Unmounting /home would require that you kick all users off for example,
> unmounting /var/www would require stopping apache, etc.

This is absolutely untested but it could work: mount / to /mnt and delete
the data from there. Dig into mount(8) and test this somewhere outside
the production area:

--bind Remount  a  subtree  somewhere  else  (so that its contents are
       available in both places). See above.

But again, this is untested and nothing more but a wild guess.

Frank.