[Linux-cluster] GFS2 over NFS4

[Fabio M. Di Nitto]

On 04/23/2015 12:11 PM, Thorvald Hallvardsson wrote:
> Hi guys,
> 
> I need some help and answers related to share GFS2 file system over NFS.
> I have read the RH documentation but still some things are a bit unclear
> to me.
> 
> First of all I need to build a POC for the shared storage cluster which
> initially will contain 3 nodes in the storage cluster. This is all going
> to run as a VM environment on Hyper-V. Generally the idea is to share
> virtual VHDX across 3 nodes, put LVM and GFS2 on top of it and then
> share it via NFS to the clients. I have got the initial cluster built on
> Centos 7 using pacemaker. I generally followed RH docs to build it so I
> ended up with the simple GFS2 cluster and pacemaker managing fencing and
> floating VIP resource.

Interesting, what fencing solution did you use?

Fabio

> 
> Now I'm wondering about the NFS. RedHat documentation is a bit
> conflicting or rather unclear in some places and I found quite few
> manuals on the internet about similar configuration and generally some
> of them suggest to mount the NFS share on the clients with nolock option
> RH docs mention local flock and I got confused about what supposed to be
> where. Of course I don't know if my understanding is correct but the
> reason to "disable" NFS locking is because GFS2 is already doing it
> anyway via DLM so there is no need for NFS to do same thing what
> eventually mean that I will have some sort of double locking mechanism
> in place. So first question is where I suppose to setup locks or rather
> no locks and how the export should look like ?
> 
> Second thing is I was thinking about going a step forward and use NFS4
> for the exports. However from what I have read about NFS4 it does
> locking by default and there is no way to disable them. Does that mean
> NFS4 is not suitable in this case at all ?
> 
> That's all for now.
> 
> I appreciate your help.
> 
> Thank you.
> TH
> 
>