[Gluster-users] Renaming a file in a distributed volume

[Brian Candler]

On Sat, Oct 13, 2012 at 05:05:08PM +0200, Stephan von Krawczynski wrote:
> On Sat, 13 Oct 2012 15:52:56 +0100
> Brian Candler <B.Candler at pobox.com> wrote:
> 
> > In a distributed volume (glusterfs 3.3), files within a directory are
> > assigned to a brick by a hash of their filename, correct?
> > 
> > So what happens if you do "mv foo bar"? Does the file get copied to another
> > brick? Is this no longer an atomic operation?
> > 
> > Thanks,
> > 
> > Brian.
> 
> In fact it has never been atomic.
> Take a look at my corresponding bug report from "back then"...
> You can use a small script to show it is not.

I hunted around, I couldn't find much in bugzilla apart from
https://bugzilla.redhat.com/show_bug.cgi?id=762766
(seems to be more about replicated volumes). I couldn't find any bugs
containing "skraw", but I'm probably just driving bugzilla wrongly.

I did find this recent posting though:
http://permalink.gmane.org/gmane.comp.file-systems.gluster.devel/2888
Is this what you're talking about? This is about an old version of glusterfs
but the version used is not specified as far as I can see.

Anyway, I think my question is answered. Normally I would create a file as
xxx.tmp, sync and then rename it to xxx, to protect against a
partially-created file; but for large files this looks like it's not a good
approach for glusterfs with a distributed volume.

Thanks,

Brian.