[Ocfs2-devel] [PATCH 0/6] nocontrold: Eliminating ocfs2_controld

[Mark Fasheh]

On Fri, Sep 06, 2013 at 02:13:00PM -0500, Goldwyn Rodrigues wrote:
> Hi Lars,
> 
> On 09/06/2013 06:22 AM, Lars Marowsky-Bree wrote:
> > On 2013-09-05T22:26:56, Goldwyn Rodrigues <rgoldwyn at suse.de> wrote:
> >
> > Hi Goldwyn,
> >
> > thanks! This looks really good.
> >
> >> This is an effort of removing ocfs2_controld.pcmk and getting ocfs2 DLM
> >> handling up to the times with respect to DLM (>=4.0.1) and corosync
> >> (2.3.x). AFAIK, cman also is being phased out for a unified corosync
> >> cluster stack.
> >
> > That's clearly necessary, also to bring OCFS2 more uptodate with the
> > latest happenings in the GFS2 world; it'll allow both file systems to
> > share exactly the same cluster stack.
> >
> >> https://github.com/goldwynr/ocfs2-tools branch: nocontrold
> >> Currently, not many checks are present in the userspace code,
> >> but that would change soon.
> >
> > There's one question I have; how will this handle
> >
> > - the "old" user-space code starting on a new kernel,
> 
> The ocfs2_controld.pcmk will refuse to start because of absence of the 
> control device created by the kernel. Of course, this would deny mounts 
> as well.

Do we know how the GFS2 project handled this case? It's going to be a major
problem for people if a kernel update horks their cluster fs.


> > Is there anything we can do to at least provide a meaningful error
> > message in the first case? The second should be easier to handle.
> 
> Yes, we can capture the error code and ask the user to upgrade in the 
> second case. However, for the first case mount.ocfs2 would give a 
> cluster connect failure because ocfs2_controld is not present.
> 
> On a different note, we should consider increasing the kernel module 
> version shown in dmesg to be in sync with the userspace tools and/or 
> possibly increase the version number of both tools and kernel module.

That shouldn't be a problem, the numbers are mostly there for us Ocfs2 devs.
	--Mark

--
Mark Fasheh