trapni at gmail
Jun 14, 2012, 5:09 PM
Post #7 of 10
Re: instances loosing IP address while running, due to No DHCPOFFER
[In reply to]
many many thanks for all your replies, and while already having raised the
just by now, I'll have now enough time to sleep to actually apply the
Yes, I am running in VLAN-mode, since this is also the propagated way.
Maybe OpenStack (nova-network) should check the version number of dnsmasq
if running in vlan mode, it really should issue a (critical) warning into
especially where this kind of error can lead to disasters in datacenters. :)
I also hope that Ubuntu 12.04 will pick up this patch soon enough, so the
end up in a patch-dominated distribution :-)
Good night all,
On Fri, Jun 15, 2012 at 1:16 AM, Narayan Desai <narayan.desai [at] gmail>wrote:
> I vaguely recall Vish mentioning a bug in dnsmasq that had a somewhat
> similar problem. (it had to do with lease renewal problems on ip
> aliases or something like that).
> This issue was particularly pronounced with windows VMs, apparently.
> On Thu, Jun 14, 2012 at 6:02 PM, Christian Parpart <trapni [at] gmail>
> > Hey,
> > thanks for your reply. Unfortunately there was no process restart in
> > nova-network nor in dnsmasq,
> > both processes seem to have been up for about 2 and 3 days.
> > However, why is the default dhcp_lease_time value equal 120s? Not having
> > this one overridden
> > causes the clients to actually re-acquire a new DHCP lease every 42
> > (at least on my nodes),
> > which is completely ridiculous.
> > OTOH, I took a look at the sources (linux_net.py) and found out, why the
> > max_lease_time is
> > set to 2048, because that is the size of my network.
> > So why is the max lease time the size of my network?
> > I've written a tiny patch to allow overriding this value in nova.conf,
> > will submit it to launchpad
> > soon - and hope it'll be accepted and then also applied to essex, since
> > is a very straight forward
> > few-liner helpful thing.
> > Nevertheless, that does not clarify on why now I had 2 (well, 3 actually)
> > instances getting
> > no DHCP replies/offers after some hours/days anymore.
> > The one host that caused issues today (a few hours ago), I fixed it by
> > rebooting the instance,
> > however, just about 40 minutes later, it again forgot its IP, so one
> > say, that it
> > maybe did not get any reply from the dhcp server (dnsmasq) almost right
> > after it got
> > a lease on instance boot.
> > So long,
> > Christian.
> > On Thu, Jun 14, 2012 at 10:55 PM, Nathanael Burton
> > <nathanael.i.burton [at] gmail> wrote:
> >> Has nova-network been restarted? There was an issue where nova-network
> >> signalling dnsmasq which would cause dnsmasq to stop responding to
> >> yet appear to be running fine.
> >> You can see if killing dnsmasq, restarting nova-network, and rebooting
> >> instance allows it to get a dhcp address again ...
> >> Nate
> >> On Jun 14, 2012 4:46 PM, "Christian Parpart" <trapni [at] gmail> wrote:
> >>> Hey all,
> >>> I feel really sad with saying this, now, that we have quite a few
> >>> instances in producgtion
> >>> since about 5 days at least, I now have encountered the second instance
> >>> loosing its
> >>> IP address due to "No DHCPOFFER" (as of syslog in the instance).
> >>> I checked the logs in the central nova-network and gateway node and
> >>> dnsmasq still to reply on requests from all the other instances and it
> >>> even
> >>> got the request from the instance in question and even sent an OFFER,
> >>> of what
> >>> I can tell by now (i'm investigating / posting logs asap), but while it
> >>> seemed
> >>> that the dnsmasq sends an offer, the instances says it didn't receive
> >>> - wtf?
> >>> Please tell me what I can do to actually *fix* this issue, since this
> >>> by far very fatal.
> >>> One chance I'd see (as a workaround) is, to let created instanced
> >>> retrieve
> >>> its IP via dhcp, but then reconfigure /etc/network/instances to
> >>> with
> >>> static networking setup. However, I'd just like the dhcp thingy to get
> >>> fixed.
> >>> I'm very open to any kind of helping comments, :)
> >>> So long,
> >>> Christian.
> >>> _______________________________________________
> >>> Mailing list: https://launchpad.net/~openstack
> >>> Post to : openstack [at] lists
> >>> Unsubscribe : https://launchpad.net/~openstack
> >>> More help : https://help.launchpad.net/ListHelp
> > _______________________________________________
> > Mailing list: https://launchpad.net/~openstack
> > Post to : openstack [at] lists
> > Unsubscribe : https://launchpad.net/~openstack
> > More help : https://help.launchpad.net/ListHelp