Open Stack

On Thu, 2021-07-08 at 09:18 +0100, Mark Goddard wrote:
> On Tue, 6 Jul 2021 at 23:18, J-P Methot <jp.methot at planethoster.info> wrote:
> > 
> > Hi,
> > 
> > I'm about ready to go into production with kolla, but one small issue
> > remains. On regular Openstack deployments, I would use the
> > libvirt-guests service to ensure that VMs on hosts always shutdown
> > cleanly when the host shuts down. This is to prevent database issues
> > which may happen on guests during forced, unclean shutdowns.
> > 
> > At first glance, Kolla doesn't seem to install this service or anything
> > similar that would ensure clean shutdown of guests when the host shuts
> > down. I have found in the github source, in the tools folder, a systemd
> > script that is supposed to do that, but it tries to execute
> > /usr/libexec/libvirt-guests.sh shutdown in the libvirt container, which
> > doesn't exist there.
> > 
> > Does Kolla already ensure clean shutdown automatically, or is there a
> > script I'm missing that could make this work?
> 
> Hi J-P Methot,
> 
> I'm aware of the scripts you've mentioned, but haven't tried them. I
> think in general we would migrate workloads away from compute nodes
> before rebooting.
thats pretty hevey handed.
live migration is not an operation that should be used lightly.
there are 0 SLAs for geust performance, packet loss or similar side
effect of live migration.

live migration should almost never be used for hevily loaded guest.

having the ablity to ues the libvirt-guest service would be quite useful when people can take the
outage of the vm or where the vm cannot be live migrated. guests with vGPU for example cant be live migrated
guest with 512GB of persitent memory can technically be migrated but it will take 10s or minutes unless you have a very fast network connection.


i actully  tough this was already shiped with kolla-ansible but maybe not?
i had it on my home cloud but it may have com in when in from a different package i installed on the host.
> 
> Thanks,
> Mark
> > 
> > 
>