Hello, Is it possible that, during snapshotting, libvirt just tears down virtual interface at some point, and then re-creates it, with hairpin_mode disabled again? This bugfix [https://bugs.launchpad.net/nova/+bug/933640] implies that fix works on spawn of instance. This means that upon resume after snapshot, hairpin is not restored. May be if we insert the _enable_hairpin() call in snapshot procedure, it helps. We're currently investigating this issue in one of our environments, hope to come up with answer by tomorrow.
-- Best regards, Oleg On Wed, Aug 22, 2012 at 11:29 PM, Sam Su <susltd...@gmail.com> wrote: > My friend has found a way to enable ping itself, when this problem > happened. But not found why this happen. > sudo echo "1" > > /sys/class/net/br1000/brif/<virtual-interface-name>/hairpin_mode > > I file a ticket to report this problem: > https://bugs.launchpad.net/nova/+bug/1040255 > > hopefully someone can find why this happen and solve it. > > Thanks, > Sam > > > On Fri, Jul 20, 2012 at 3:50 PM, Gabriel Hurley <gabriel.hur...@nebula.com > > wrote: > >> I ran into some similar issues with the _*enable*_hairpin() call. The >> call is allowed to fail silently and (in my case) was failing. I couldn’t >> for the life of me figure out why, though, and since I’m really not a >> networking person I didn’t trace it along too far.**** >> >> ** ** >> >> Just thought I’d share my similar pain.**** >> >> ** ** >> >> **- **Gabriel**** >> >> ** ** >> >> *From:* >> openstack-bounces+gabriel.hurley=nebula....@lists.launchpad.net[mailto: >> openstack-bounces+gabriel.hurley=nebula....@lists.launchpad.net] *On >> Behalf Of *Sam Su >> *Sent:* Thursday, July 19, 2012 11:50 AM >> *To:* Brian Haley >> *Cc:* openstack >> *Subject:* Re: [Openstack] VM can't ping self floating IP after a >> snapshot is taken**** >> >> ** ** >> >> Thank you for your support.**** >> >> ** ** >> >> I checked the file nova/virt/libvirt/connection.py, the sentence >> self._enable_hairpin(instance) is already added to the >> function _hard_reboot().**** >> >> It looks like there are some difference between taking snapshot and >> reboot instance. I tried to figure out how to fix this bug but failed. ** >> ** >> >> ** ** >> >> It will be much appreciated if anyone can give some hints.**** >> >> ** ** >> >> Thanks,**** >> >> Sam**** >> >> ** ** >> >> On Thu, Jul 19, 2012 at 8:37 AM, Brian Haley <brian.ha...@hp.com> wrote:* >> *** >> >> On 07/17/2012 05:56 PM, Sam Su wrote: >> > Hi, >> > >> > Just This always happens in Essex release. After I take a snapshot of >> my VM ( I >> > tried Ubuntu 12.04 or CentOS 5.8), VM can't ping its self floating IP; >> before I >> > take a snapshot though, VM can ping its self floating IP. >> > >> > This looks closely related to >> https://bugs.launchpad.net/nova/+bug/933640, but >> > still a little different. In 933640, it sounds like VM can't ping its >> self >> > floating IP regardless whether we take a snapshot or not. >> > >> > Any suggestion to make an easy fix? And what is the root cause of the >> problem?**** >> >> It might be because there's a missing _enable_hairpin() call in the >> reboot() >> function. Try something like this... >> >> nova/virt/libvirt/connection.py, _hard_reboot(): >> >> self._create_new_domain(xml) >> + self._enable_hairpin(instance) >> self.firewall_driver.apply_instance_filter(instance, >> network_info) >> >> At least that's what I remember doing myself recently when testing after a >> reboot, don't know about snapshot. >> >> Folsom has changed enough that something different would need to be done >> there. >> >> -Brian**** >> >> ** ** >> > > > _______________________________________________ > Mailing list: https://launchpad.net/~openstack > Post to : openstack@lists.launchpad.net > Unsubscribe : https://launchpad.net/~openstack > More help : https://help.launchpad.net/ListHelp > >
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