[Samba] GPFS on Linux exported via Samba to Windows Clients, locking issue

Jonathan Buzzard jonathan at buzzard.me.uk
Mon May 28 02:12:05 MDT 2012

On Sat, 2012-05-26 at 09:45 +0200, steve wrote:
> On 24/05/12 19:52, Leonard Degollado wrote:
> >
> > I have a 3-node GPFS on Linux Cluster (3.4.0-12) with Samba 3.6.5
> > The problem  is with file locking across the Cluster.
> > Windows Client-1 maps the GPFS directory-1 from GPFS node-1 and initiates a
> > Write of File-1
> > Windows Client-2 maps the GPFS directory-1 from GPFS node-2 and should only
> > have READ access but not Modify/Delete/Rename access to File-1.
> >
> > However, Windows Client-2 is able to Modify, Delete and Rename File-1
> > instead of being prevented by the locks.
> >
> > If both Windows Clients (1 and 2) both map to GPFS node-1, the locking
> > mechanism works as designed.  Client-2 can Read but cannot
> > Modify/Delete/Rename File-1.
> > What are all the required parameters that should be specified in the
> > smb.conf file to enable the locking to work across the GPFS Cluster when
> > various Clients map to different nodes?
> >
> > I have defined and tested every smb locking parameter combination without
> > any success.
> >
> >
> >
> > Leonard
> Hi Leanard
> It seems to be program dependent. We can only get file locking to work 
> with libreoffice, office 2010, gimp and inkscape. Anything else, and the 
> file can be opened rw by anyone, even if it is open elsewhere.
> I wonder why file locking only works with certain programs?

Perhaps you need to flick one of the "undocumented" make GPFS work
better with Samba switches in GPFS? Say 

    mmchconfig syncSambaMetadataOps=yes

or perhaps

   mmchconfig allowSynchronousFcntlRetries=yes

These being the two of the six "undocumented" config options that I
don't understand what they do; allowSambaCaseInsensitiveLookup,
allowWriteWithDeleteChild, cifsBypassShareLocksOnRename,
cifsBypassTraversalChecking are all rather more self explanatory and do
exactly what they say on the tin.


Jonathan A. Buzzard                 Email: jonathan (at) buzzard.me.uk
Fife, United Kingdom.

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