[Lustre-discuss] Samba and file locking

[Oleg Drokin]

Hello!

On Aug 27, 2010, at 6:41 PM, David Noriega wrote:
> But I also found out about the flock option for lustre. Should I set
> flock on all clients? or can I just use localflock option on the
> fileserver?

It depends.
If you are 100% sure none of your other clients use flocks in a way similar to samba to
guard their file accesses AND you don't export (same fs with) samba from more than one node, you
can mount with localflock on samba-exporting node.

Otherwise you need to mount with flock, but please be aware that flock is not exactly cheap in lustre,
every flock operation is a synchronous RPC plus it puts even more load on MDS and some applications
start to use flock once they see it as available resulting in possible unexpected slowdowns
(MPI apps in some IO modes without lustre ADIO driver tend to do this, I think)

Bye,
    Oleg