[Ocfs2-users] OCFS2 + Xen node

[Jorge Cabello]

Thanks Marc for all the info.

I will take a look to the links you have given me.

El jue, 08-11-2007 a las 08:35 +0100, Marc Grimme escribió:
> Hi,
> On Wednesday 07 November 2007 15:21:17 Jorge Cabello wrote:
> > Hi all,
> >
> > I'm trying to use ocfs2 as the root filesystem for xen virtual nodes. If
> > I leave ocfs2 as a module the system doesn't boot as it doesn't find a
> > supported filesystem for the root partition.
> >
> > I have also tried to include ocfs2 inside the kernel (not as a module)
> > on the virtual node to be able to mount the root partition but it also
> > doesnt work. With this option I'm not even able to mount other
> > partitions as o2cb doesn't find the module.
> When the root filesystem gets mounted by the kernel or inside the initrd all 
> prerequisites to mount a that filesystem must be met. In case of cluster 
> filesystems like OCFS2 it gets a little bit more complicated compared to 
> local filesystems like ext3. That means before mounting you'll have to have a 
> cluster running which implicitly means having network up and having started 
> ocfs services properly.
> This is not done within standard initrd. Even if you hardcompile the module 
> into the kernel the network does not get started and there is no cluster 
> configuration available in the kernel. All this and if done properly much 
> more must be done inside the initrd.
> Have a look at 
> http://www.opensharedroot.org/documentation/description-on-the-open-sharedroot-bootprocess
> >
> > Has anyone been able to do something similar to this? Do I need to do
> > anything special to include ocfs2 inside the kernel so I can mount the
> > root partition at boot?
> We've moved the root filesystem successfully onto GFS which is in this way 
> comparable to OCFS2 (see www.open-sharedroot.org). The question is not if it 
> works for XEN or not but if it works at all (but yes there need to be some 
> tweaks for getting XEN up and running I remember. If you like I can sort them 
> out again and tell you.).
> 
> I've tried to use OCFS2 as root filesystem with that sharedroot concept some 
> month ago but had problems when using berkely db based software (rpm, 
> ldap, ..). That seems to be related to no shared mmaps being available at 
> that time. With a more recent kernel that should succeed 2.6.23-.. does have 
> the shared mmap support available I've heard.
> 
> I hope that helps a bit.
>