[Linux-cluster] GFS2 on CentOS v5.2

[Steven Whitehouse]

Hi,

On Mon, 2008-12-01 at 10:59 +0100, Shaun Mccullagh wrote:
> Many thanks for the clear info.
> 
> I've installed kmod-gfs and cman-2.0.84. I notice that kmod gfs2 is loaded when I start service cman.
> I see that gfs2.ko is part of kernel-2.6.18-92.1.18.el5, which is the kernel in use on the system. 
> 
> Is this expected behaviour?
> 
> When I exec  service gfs start     should I expect gks.ko to be loaded?
> 
> Thx Again....
> 
> Shaun
> 
That all sounds about right. GFS2 was made into a kmod and then more
recently its become part of the standard kernel again. So if you have an
uptodate kernel then it should be just like any other fs. GFS is a kmod
and will remain so.

The init scripts do load some of the modules early, and also in older
kernels there was a dependency between GFS and GFS2 since they both
shared the same lock modules. In recent kernels the lock modules are no
longer shared between GFS and GFS2, in fact in Fedora lock_nolock no
longer exists for GFS2 since its been merged into GFS2 itself. There is
a plan to merge lock_dlm into GFS2 as well which will solve a problem
thats been flagged up with selinux and init scripts (mount shouldn't
need to load modules directly, but GFS2's mount does have to do this
while lock_dlm is a separate module).

Watch the cluster-devel list if you want to track progress on merging of
the lock_dlm module. I should also point out, just to remove any
possible confusion, that by lock_dlm, I mean the module which GFS2 uses
to interface to the DLM, and not the DLM itself which will obviously
remain separate,

Steve.