[Gluster-users] NFS file locking with gluster 3.7.3

[Thibault Godouet]

Thanks Niel for your helpful answer.

Regarding the locking, indeed that solves my issue. Now I'm wondering how
to monitor this. The best I have so far is get the list of RPC binds and
the TCP/UDP port in particular, and then run a lsof to find out if it is
Gluster.  Should work, but a bit indirect. If someone knows a better way
I'd be interested to know.

As for Ganesha, I saw articles explaining that it effectively removes
layers, hence why I thought NFS v3 via Ganesha would be faster than native
Gluster NFS.  Given your answer I take it there are other moving parts /
differences.  Is there a general known guideline on which is best when?
E.g. does one handle better small files than the other one or something
like that?
On 5 Aug 2015 7:06 pm, "Niels de Vos" <ndevos at redhat.com> wrote:

> On Wed, Aug 05, 2015 at 04:11:47PM +0100, Thibault Godouet wrote:
> > Looking around I get the impression that file locking (NLM) may simply
> not
> > be supported in glusterfs's built-in NFS server.
>
> This is actually supported. But note that you can not run a userspace
> NLM implementation provided by a NFS-server (Gluster/NFS or NFS-Ganesha)
> on a system that acts as an NFS-client. The Linux kernel NFS-client uses
> the lockd kernel module, and there can be only one NLM implementation be
> registered at rpcbind. Whichever service (nfs-client or nfs-server)
> starts first, will be able to register itself, the 2nd one will (mostly
> silently) fail.
>
> > I get the impression that Ganesha is aimed at supporting NFS better, and
> > presumably supports locking well, so I should give it a try (If I
> > understand well the performance is also likely to be higher, which is a
> > nice bonus!)
>
> NFS-Ganesha offers more features than Gluster/NFS. The performance is
> highly dependent on the workload, Gluster/NFS can be faster for many of
> them.
>
> Cheers,
> Niels
>
>
> >
> > If someone could confirm this that would be useful to make sure I'm going
> > in the right direction.
> >
> > Thanks,
> > Thibault.
> > On 4 Aug 2015 1:23 pm, "Thibault Godouet" <tibo92 at godouet.net> wrote:
> >
> > > Hi,
> > >
> > >
> > >
> > > I have a cluster of 2 servers running 3.7.3 with replication, and
> standard
> > > NFS (no ganesha).  This in on CentOS 6.
> > >
> > > I use CTDB with 2 virtual IPs (one for each server in a normal
> > > situation) to share the volume over NFS and CIFS (samba).
> > >
> > >
> > >
> > > fnctl() file locking doesn't seem to work when the volume is mounted
> over
> > > NFS.
> > >
> > > This is apparent with a 'svn info' (svn 1.8 if it made any difference)
> in
> > > a local working copy:
> > >
> > >
> > >
> > > $ svn info
> > > svn: E200033: Another process is blocking the working copy database, or
> > > the underlying filesystem does not support file locking; if the working
> > > copy is on a network filesystem, make sure file locking has been
> enabled on
> > > the file server
> > > svn: E200033: sqlite[S5]: database is locked, executing statement
> 'PRAGMA
> > > synchronous=OFF;PRAGMA recursive_triggers=ON;PRAGMA
> foreign_keys=OFF;PRAGMA
> > > locking_mode = NORMAL;'
> > >
> > >
> > >
> > > a strace shows:
> > >
> > >
> > >
> > > $ svn info
> > > svn: E200033: Another process is blocking the working copy database, or
> > > the underlying filesystem does not support file locking; if the working
> > > copy is on a network filesystem, make sure file locking has been
> enabled on
> > > the file server
> > > svn: E200033: sqlite[S5]: database is locked, executing statement
> 'PRAGMA
> > > synchronous=OFF;PRAGMA recursive_triggers=ON;PRAGMA
> foreign_keys=OFF;PRAGMA
> > > locking_mode = NORMAL;'
> > >
> > >
> > >
> > > Everything seems to work fine on native Gluster (FUSE) mounts: the same
> > > 'svn info' works nicely.
> > >
> > > I can't really use native mounts due to the performance hit (many small
> > > files) and the fact I would need to install the gluster client
> software on
> > > every server.
> > >
> > >
> > >
> > > Is fnctl() file locking supported in Gluster NFS mounts?  If so, any
> idea
> > > why it doesn't work for me?
> > >
> > >
> > >
> > > Thanks,
> > >
> > > Thibault.
> > >
>
> > _______________________________________________
> > Gluster-users mailing list
> > Gluster-users at gluster.org
> > http://www.gluster.org/mailman/listinfo/gluster-users
>
>
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