[ClusterLabs] Live migration not working on shutdown

[Ken Gaillot]

On 10/26/2016 06:12 AM, Rainer Nerb wrote:
> Hello all,
> 
> we're currently testing a 2-node-cluster with 2 vms and live migration
> on CentOS 7.2 and Pacemaker 1.1.13-10 with disks on iSCSI-targets and
> migration via ssh-method.
> 
> Live migration works, if we issue "pcs resource move ...", "pcs cluster
> standby", "pcs cluster stop" and even "systemctl rescue".
> The latter only worked, after adding the following additional
> dependencies to pacemaker.service and leaving the management of those
> services to systemd:
> 
>   * After/Requires=systemd-machined.service
>   * After/Requires=systemd-machine-id-commit.service
>   * After/Requires=remote-fs.target
>   * After/Requires=libvirtd.service
>   * After/Requires=iscsi.service
>   * After/Requires=iscsid.service
>   * After/Requires=sshd.service

This makes sense when clustered resources depend on services that aren't
themselves managed by the cluster. It's dependent on your situation, so
it's not something that pacemaker can solve generically.

You may already be aware, but the easiest way to add such requirements
is to put them in a systemd unit override, e.g.
/etc/systemd/system/pacemaker.service.d/dependencies.conf.

> When shutting down or rebooting migration fails and not even the regular
> shutdown of the vms succeeds. Systemd seems to tear down the vms by
> terminating something they depend on.
> 
> Is this a known issue? Did we miss any further dependencies?

There was a shutdown issue when using systemd-class cluster resources
(systemd: instead of ocf:), but I believe that was fixed in the package
you're using, and it's probably not relevant here anyway.

It does sound like there's another dependency, but I don't know what.

What log messages do you see on the failure?

> 
> Tia
> Rainer
> 
> 
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