[ovirt-users] help with sriov vdsm hook?

[Darrell Budic]

On May 12, 2014, at 7:32 AM, Itamar Heim <iheim at redhat.com> wrote:

> On 05/12/2014 07:57 AM, Dan Kenigsberg wrote:
>> On Sun, May 11, 2014 at 05:44:35PM -0400, Itamar Heim wrote:
>>> On 05/08/2014 02:54 PM, Darrell Budic wrote:
>>>> Anyone gotten the SRIOV hook to work with Solar Flare 10g cards? Any advice?
>>>> 
>>>> I've gotten the hooks installed on my host nodes, and added a string to my engine. The card is up in SRIOV "mode" on the host and virtual instances are available. I can see the hooks running in the vdsm logs, but can't tell what they are doing from there. They are not attaching the sriov card instance to my VM though, so I'm at a loss.
>>> 
>>> you can compare the generated livirt xml send to qemu by vdsm and
>>> compare to what you expected to happen by the hook.
>> 
>> You may also share the bit of vdsm.log from vmCreate until failure.

I haven’t had time to get back to this yet, but I’ll share logs the next time I get to try it. May not be for a couple of weeks, about to take a vacation. But from memory, it’s not adding anything at all to the xml, so I’m not sure if my custom property string is wrong, or if it’s just not working for some other reason.


>> As an aside, it'd be really nice to have hooks register with the engine and add proper custom strings to the setup. Failing that, some explicit documentation on EXACTLY what string should be used for the hook would be nice. My first pass at it resulted in an improper string that caused my host to crash/hang and reboot when I attempted to start a VM with it the first time.
>>> 
>>> 
>>> each hook has a README - maybe send a patch to elaborate more on the
>>> one not clear enough to you?
>> 
>> I think that Darrel means something like
>> 
>>     Bug 1086329 - [RFE] semi-automatic hook registration
>> 
>> (or maybe a bit less fancy). It would be cool to add some introspection
>> to the hook framework, so that Engine learns about available hooks and
>> their custom properties from the nodes.
>> 
> 
> engine learns about deployed hooks (and shows them in the gui) based on vdsm reporting them.
> vdsm could report also the custom properties regex string, but would probably need to version it, since engine would need to pick the 'one' regex from multiple hosts reporting different things for same hook.

Exactly this. I didn’t find any documentation for what the strings should be, so I’m guessing a bit based on reading the code. My first try forgot to include the “sriov=“ bit, and if you just pass “eth0” to that hook, you’ll crash the whole node. Or at least I did once (if there were other vms running on that node), and just dropped networking on another occasion before I realized I’d passed an incomplete string. Seems like something that would be really nice to have auto set so you can’t screw it up, especially if it could crash more than just the VM.

I think it’d be fine to not have a properly be available if all the host nodes in a cluster didn’t agree on what the string/version number should be. Display an alert for the node if it’s out of sync or something so it’s easy to track down.