[Linux-cluster] how to use fence_xvmd fence option on Rhel5

[Lon Hohberger]

On Fri, May 11, 2007 at 06:49:57PM +0200, carlopmart wrote:
> Hi all,
> 
>  RedHat's documentation about using fence_xvmd and fence_xvm it isn't very 
> clear, almost for me.
> 
>  I need to use another fence device than manual on my actual two-node 
>  cluster suite under xen. To do this I think to use fence_xvmd and fence_xvm 
> options. But how? What are the minimum requeriments to use it?. My only 
> option is:

>  - Dom0 runs fence_xvmd and domU two-nodes runs fence_xvm clients, but, 
>  will dom0 be need act as a part of the cluster?? or not?

Dom0 should be a part of *its own* cluster - which is not part of the VM
cluster.

It can be a 1-node cluster.

(1) So, configure dom0 like a 1-node cluster with no fencing.
(2) Add "<fence_xvmd/>" to cluster.conf in dom0 as a child of the
"<cluster>" tag.
(3) dd if=/dev/urandom of=/etc/cluster/fence_xvm.key
(4) scp /etc/cluster/fence_xvm.key root at virtual_node_1:/etc/cluster
(5) scp /etc/cluster/fence_xvm.key root at virtual_node_2:/etc/cluster
(6) Start cman on dom0 - this should start fence_xvmd for you


For testing correct fence_xvm.key distribution, try:

(1) Log in to domain-0 in one window
(2)    killall fence_xvmd 
(3)    fence_xvmd -fddddddddd
(4) Log in to a guest domain from another window
(5)    fence_xvm -H <domain_name> -o null

If everything works, you should see all kinds of useless garbage on the
screen in the fence_xvmd window.

If that works, add fence_xvm to the guest-domain cluster using
system-config-cluster or Conga. (All you need is the domain name which
corresponds to the cluster name for each guest domain node).

-- 
Lon Hohberger - Software Engineer - Red Hat, Inc.