[ovirt-users] Autostart VMS

[Nir Soffer]

On Fri, Apr 8, 2016 at 9:33 PM, Brett I. Holcomb <biholcomb at l1049h.com> wrote:
> On Fri, 2016-04-08 at 19:25 +0300, Nir Soffer wrote:
>
> On Fri, Apr 8, 2016 at 7:17 PM, Brett I. Holcomb <biholcomb at l1049h.com>
> wrote:
>
> On Fri, 2016-04-08 at 11:31 +0200, Martin Sivak wrote:
>
> Hi,
>
>
> I set highly available on, did not pin to any host, and also set the
> watchdog which should reset if they go down but I'm not sure that will start
> them if the host comes up and the VMs are not running.  I'll look at the CLI
> first.
>
>
> The engine will try to keep the VM running. So if one host goes down,
> it will restart the VM on some other host automatically. We will also
> migrate the VM (or some other to free resources) when the current host
> gets too loaded. We do not require any migration addons, it just
> works. But of course we have usually more hosts in a cluster to make
> this possible.
>
> I do not really remember what happens when all hosts are restarted
> (power outage) though as that is quite special case.
>
> Regards
>
> --
> Martin Sivak
> SLA / oVirt
>
>
>
> Thanks.  I only have one host so who knows what will happen.  I'm working on
> a script that will basically emulate what VMware does - start VMS in a given
> order at startup of the host/engine.  I'll also file a feature request.
>
>
> Why do you care about the order?
>
> Isn't it enough to restart all the vms after a host was restarted?
>
> Nir
>
>
> Does the Engine start all VMs after the host is powered up and the engine
> running if I set a watchdog on a VM?  I know it will try to restart the VM
> if it goes down once oVirt is up and running.   If it will start the VMs at
> reboot time that helps.

I think only HA vms are restarted. Adding Michal to add more info on this.

> The reason for the order is that you need some servers such as DNS, file
> servers, up first before other systems can resolve addresses or mount
> shares.  For Windows you need domain controllers running before the other
> windows systems that are part of the domain.  For applications such as Lotus
> Notes the servers had to come up in the correct order.

Lets say you have a way to order the vms when some vms are down.

What will happen to when dns, file servers or domain controller will crash?
Do you have to restart all the vms depending on them or they can
recover and detect that vm they depend on were restarted?

Seems that what you need is a systemd for your data center - every
host define the host it depends on, and the system generate the
correct order to start the vms, starting vms in the same time when
possible.

Please reply also to the list, this thread may be useful to others.

Nir

> On Wed, Apr 6, 2016 at 9:10 PM, Brett I. Holcomb <biholcomb at l1049h.com>
> wrote:
>
> On Wed, 2016-04-06 at 13:42 -0400, Adam Litke wrote:
>
> On 06/04/16 01:46 -0400, Brett I. Holcomb wrote:
>
> In VMware we could setup guests to autostart when the host started and
> define the order.  Is that doable in oVirt?  The only thing I've seen
> is the watchdog and tell it to reset but nothing that allows me to
> define who starts up when and if they autostart.  I assume it's there
> but I must be missing it or haven't found it in the web portal.
>
>
> In oVirt guests aren't tied to a host by default (although you can set
> them to run only on a specific host if you want).  The closest thing I
> can think of would be the High Availability features (VM->Edit).
> oVirt will try to restart highly available VMs if they go down.  You
> can also set the priority for migration and restart in that pane.
> Hopefully a combination of host pinning and the  high availability
> settings will get you close enough to where you want to be.
>
> Otherwise, you could always do some scripting with the ovirt REST API
> using the SDK or CLI.
>
>
> If you had the VMware migration extra add-on you could have hosts move as
> needed so they were not tied to any host either but we could set a startup
> order and specify auto, manual so that once the host started the VMs were
> brought up as specified no matter what host they were running on.
>
> I am running hosted-engine deployment with the Engine VM on the host.
>
> I set highly available on, did not pin to any host, and also set the
> watchdog which should reset if they go down but I'm not sure that will start
> them if the host comes up and the VMs are not running.  I'll look at the CLI
> first.
>
> It would be nice if oVirt added this feature as it's really required for
> large installations and is a help for any size installation, even small
> ones.
>
>
>
>
> _______________________________________________
> Users mailing list
> Users at ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
>
>
> _______________________________________________
> Users mailing list
> Users at ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
>