[ClusterLabs] Fencing libvirt

[Ken Gaillot]

On Fri, 2018-06-15 at 21:39 -0400, Jason Gauthier wrote:
> Greetings,
> 
>    Previously, I was using fiber channel with block devices.  I used
> sbd to fence the disks, by creating a small block device, and then
> using stonith to fence the physical disk block.
> 
> However, I had some reliability issues with that (I believe it was
> the
> fibre channel interfacing, not clustering).  So, I've moved
> everything
> to NFS.

Another possibility would be to use qdevice with a third host, so that
the cluster has true quorum, and then you can use sbd with hardware
watchdog only (no need for a shared disk).

> My only resources are virtual machines running with KVM.    So, I am

The VMs are resources, or nodes? The libvirt fence agents are for
fencing VMs used as full cluster nodes.

> trying to figure out what I should fence.  I saw stonith has a
> module,
> external/libvirt, and that seems like it might work. But I can't seem
> to figure out how to use it with my crm config.
> 
> I've attempted this:
> primitive st_libvirt stonith:external/libvirt \
>         params hypervisor_uri="qemu:///system" hostlist="alpha beta"
> \
>         op monitor interval=2h \
>         meta target-role=Stoppedprimitive st_libvirt
> stonith:external/libvirt \
>         params hypervisor_uri="qemu:///system" hostlist="alpha beta"
> \
>         op monitor interval=2h
> 
> But, I am not sure this is the correct syntax.  The nodes are alpha,
> and beta.
> 
> Any pointers appreciated.
-- 
Ken Gaillot <kgaillot at redhat.com>