<div dir="ltr">Would having an event we push in the bus be sufficient?<div>I can see about having this added to our nova contributor's work queues.</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Dec 3, 2014 at 2:19 AM, Daniel P. Berrange <span dir="ltr"><<a href="mailto:berrange@redhat.com" target="_blank">berrange@redhat.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="HOEnZb"><div class="h5">On Tue, Dec 02, 2014 at 08:48:52PM -0500, Steve Gordon wrote:<br>
> ----- Original Message -----<br>
> > From: "Stefano Maffulli" <<a href="mailto:stefano@openstack.org">stefano@openstack.org</a>><br>
> > To: "Daniel P. Berrange" <<a href="mailto:berrange@redhat.com">berrange@redhat.com</a>>, <a href="mailto:Enterprise-wg@lists.openstack.org">Enterprise-wg@lists.openstack.org</a><br>
> ><br>
> > hi Daniel,<br>
> ><br>
> > during today's meeting for the Win The Enterprise working group we<br>
> > noticed libvirtWatchdog. The wiki page<br>
> > <a href="https://wiki.openstack.org/wiki/LibvirtWatchdog" target="_blank">https://wiki.openstack.org/wiki/LibvirtWatchdog</a> is authored by you<br>
> > originally so I'm reaching out to learn more about the status of this<br>
> > feature.<br>
> ><br>
> > In the WTE team, one of the priorities is to understand the status of<br>
> > features that allow non-ephemeral (persistent) workloads on OpenStack<br>
> > (aka the "pet" use case). libvirtWatchdog was mentioned during a session<br>
> > in Paris, saying that it currently supports KVM and Linux guests only.<br>
> ><br>
> > What are the plans for its future (can/should it be extended to other<br>
> > guests/hypervisors)? Who's maintaining it at the moment? Is there any<br>
> > other documentation besides the wiki page?<br>
><br>
> I'll take a crack at it and then Dan can tell me how wrong I am since it's probably my fault it was in the etherpad ;). The watchdog feature in OpenStack is exposing capabilities in the underlying Libvirt [1] and Qemu [2][3] layers which allow you to attach an i6300esb watchdog device to the guest and assign a lifecycle action to take if it is triggered. Fundamentally there's nothing preventing other hypervisor projects from implementing this, I'm not sure which ones if any actually have however (and when I cover the second part of your question below it might become clear why).<br>
><br>
> As to why it only works with Linux guests (or more accurately why it doesn't work for Windows - I wouldn't be surprised if the BSD family or other OSes do support it to some degree but I've never checked) I believe it was originally intended to but there were a few issues uncovered during the chase, in particular:<br>
><br>
> 1) The default Window's driver for the device only displays the PCI information for it (it doesn't actually do anything with the device).<br>
><br>
> 2) The Intel driver for this device on Windows only ever worked with 32-bit editions of Windows.<br>
><br>
> 3) The Intel driver for this device on Windows always assumes it's in a specific PCI slot.<br>
><br>
> 4) There's no framework within Windows for triggering a watchdog device and we weren't able to determine if there were any Windows applications capable of triggering one either.<br>
><br>
> Basically while you can attach the device to a Windows guest for it to actually be used it would require someone to write a proper driver for the device that works on Windows and there would need to be applications that know how to actually make use of it. In the Linux case I believe there is wider support for it and it can be triggered by common panics and lockups (Rich's blog [3] gives some more examples).<br>
><br>
> For the gorier details see: <a href="https://bugzilla.redhat.com/show_bug.cgi?id=610063" target="_blank">https://bugzilla.redhat.com/show_bug.cgi?id=610063</a>.<br>
<br>
</div></div>Yep, that's pretty much it.<br>
<br>
Also note there's a missing feature in Nova in that we have no mechanism<br>
to notify the end user when a watchdog fires on their VMs. Libvirt has<br>
this notification ability but we've nowhere to send this info in OpenStack.<br>
We need some kind of formal alerting system to get a message back to the<br>
end user (or to an ochestration tool like Heat), so they can take action<br>
when it fires.<br>
<br>
Regards,<br>
Daniel<br>
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</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr"><div>Jason Venner<br></div>Vice President and Chief Architect<br>Mirantis Inc<br><div><br></div><div><br></div></div></div>
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