Hi Yaniv,

On Sun, Aug 7, 2016 at 9:37 PM, Ekin Meroğlu <ekin.meroglu@linuxera.com> wrote:
Hi,

Just a reminder, if you have power management configured, first turn that off for the host - when you restart vdsmd with the power management configured, engine finds it not responding and tries to fence (e.g. reboot) the host.

That's not true - if it's a graceful restart, it should not happen.

​Can you explain this a little more? Is there a mechanism to prevent fencing on this scenario? 

In two of our customers' production systems we've experienced this exact behavior (i.e. engine fencing the host while restarting vdsm service manually) for a number of times, and we were specifically advised by Red Hat Support to turn off PM before restarting service. I'd like to to know if we have a better / easier way to restart vdsm. ​

​btw, ​b
oth of the environments were RHE​V-H based RHEV 3.5 clusters, and both we were busy systems, so restarting vdsm service took quite a long time. I'm guessing this might be a factor.

Regards,
 
 

Other than that, restarting vdsmd has been safe in my experience...

Regards,  

On Thu, Aug 4, 2016 at 6:10 PM, Nicolás <nicolas@devels.es> wrote:


El 04/08/16 a las 15:25, Arik Hadas escribió:

----- Original Message -----
El 2016-08-04 08:24, Arik Hadas escribió:
----- Original Message -----

El 04/08/16 a las 07:18, Arik Hadas escribió:
----- Original Message -----
Hi,

We're running oVirt 4.0.1 and today I found out that one of our hosts
has all its VMs in an unknown state. I actually don't know how (and
when) did this happen, but I'd like to restore service possibly without
turning off these machines. The host is up, the VMs are up, 'qemu'
process exists, no errors, it's just the VMs running on it that have a
'?' where status is defined.

Is it safe in this case to simply modify database and set those VM's
status to 'up'? I remember having to do this a time ago when we faced
storage issues, it didn't break anything back then. If not, is there a
"safe" way to migrate those VMs to a different host and restart the
host
that marked them as unknown?
Hi Nicolás,

I assume that the host these VMs are running on is empty in the
webadmin,
right? if that is the case then you've probably hit [1]. Changing their
status to up is not the way to go since these VMs will not be monitored.
Hi Arik,

By "empty" you mean the webadmin reports the host being running 0 VMs?
If so, that's not the case, actually the VM count seems to be correct
in
relation to "qemu-*" processes (about 32 VMs), I can even see the
machines in the "Virtual machines" tab of the host, it's just they are
all marked with the '?' mark.
No, I meant the 'Host' column in the Virtual Machines tab but if you
see
the VMs in the "Virtual machines" sub-tab of the host then run_on_vds
points to the right host..

The host is up in the webadmin as well?
Can you share the engine log?

Yes, the host is up in the webadmin, there are no issues with it, just
the VMs running on it have the '?' mark. I've made 3 tests:

1) Restart engine: did not help
2) Check firewall, seems to be ok.
2) PostgreSQL: UPDATE vm_dynamic SET status = 1 WHERE status = 8; :
After a while, I see lots of entries like this:

      2016-08-04 09:23:10,910 WARN
[org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector]
(DefaultQuartzScheduler4) [6ad135b8] Correlation ID: null, Call Stack:
null, Custom Event ID: -1, Message: VM xxx is not responding.

I'm attaching the engine log, but I don't know when did this happen for
the first time, though. If there's a manual way/command to migrate VMs
to a different host I'd appreciate a hint about it.

Is it safe to restart vdsmd on this host?
The engine log looks fine - the VMs are reported as not-responding for
some reason. I would restart libvirtd and vdsmd then

Is restarting those two daemons safe? I mean, will that stop all qemu-* processes, so the VMs marked as unknown will stop?


Thanks.

Thanks.

Yes, there is no other way to resolve it other than changing the DB but
the change should be to update run_on_vds field of these VMs to the host
you know they are running on. Their status will then be updates in 15
sec.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1354494

Arik.

Thanks.

Nicolás

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--
Ekin Meroğlu Red Hat Certified Architect 

linuxera Özgür Yazılım Çözüm ve Hizmetleri 
T +90 (850) 22 LINUX | GSM +90 (532) 137 77 04
www.linuxera.com | bilgi@linuxera.com

_______________________________________________
Users mailing list
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http://lists.ovirt.org/mailman/listinfo/users





--
Ekin Meroğlu Red Hat Certified Architect 

linuxera Özgür Yazılım Çözüm ve Hizmetleri 
T +90 (850) 22 LINUX | GSM +90 (532) 137 77 04
www.linuxera.com | bilgi@linuxera.com