Re: [Nbd] Exporting block-devices an copyonwrite

[Wouter Verhelst <w@...112...>]

On Tue, Nov 02, 2010 at 10:48:56AM +0100, Wilhelm wrote:
> Am 02.11.2010 10:43, schrieb Wouter Verhelst:
> > On Sun, Oct 31, 2010 at 10:27:10AM +0100, Wilhelm wrote:
> >   
> >> Hi all,
> >>
> >> a simple question: if I export a block-device, e.g. say /dev/sdd1 and
> >> set copyonwrite = true, where are the cow-files placed in the filesystem?
> >>     
> > Right next to the original file. 
> 
> For example above, will I get a regular file
> /dev/sdd1-192.168.1.1-1234.diff ?

Yes, if you're trying to export a partition directly with the
copyonwrite option set, that's what nbd-server will try to do.

However you can work around it by using a symlink, and specifying the
name of that symlink as the exported file. In that case, nbd-server will
create the diff file next to the symlink.

> > There's currently no way to change
> > that, though I've had people ask me to make that possible.
> 
> If the above is true, this would be extremly helpful.

I'll get around to doing that eventually, but of course patches are
always welcome :-)

-- 
The biometric identification system at the gates of the CIA headquarters
works because there's a guard with a large gun making sure no one is
trying to fool the system.
  http://www.schneier.com/blog/archives/2009/01/biometrics.html