Networking fails for VM running on Centos6.7.Works on Centos6.5
hello all i am having strange network issue with vms that are running on centos 6.7 ovirt nodes. I recently added one more ovirt node which is running centos6.7 and upgraded from centos6.5 to centos6.7 on all other nodes. All VMs running on nodes with centos6.7 as host Operating system fail to reach network gateway,but if i reboot that same host to centos6.5 kernel everything works fine(with out changing any network configuration). Initially i thought it as configuration issue but its there on all nodes.if i reboot to old kernel everything is working. I am aware about ghost vlan0 issue in centos6.6 kernel.Not aware about any issue in centos6.7 Also all my servers are up to date. All physical interfaces are in access mode VLAN connected to nexus 5k switches. working kernel- 2.6.32-431.20.3.el6.x86_64 non working kernel- 2.6.32-573.8.1.el6.x86_64 Any idea?
On Sat, Nov 28, 2015 at 08:10:06PM +0530, mad Engineer wrote:
hello all i am having strange network issue with vms that are running on centos 6.7 ovirt nodes.
I recently added one more ovirt node which is running centos6.7 and upgraded from centos6.5 to centos6.7 on all other nodes.
All VMs running on nodes with centos6.7 as host Operating system fail to reach network gateway,but if i reboot that same host to centos6.5 kernel everything works fine(with out changing any network configuration).
Initially i thought it as configuration issue but its there on all nodes.if i reboot to old kernel everything is working.
I am aware about ghost vlan0 issue in centos6.6 kernel.Not aware about any issue in centos6.7 Also all my servers are up to date.
All physical interfaces are in access mode VLAN connected to nexus 5k switches.
working kernel- 2.6.32-431.20.3.el6.x86_64
non working kernel- 2.6.32-573.8.1.el6.x86_64
Can you provide the topology of your VM network config (vlan, bond, bond options, bridge options)? Do you have an IP address on the bridge? (I have not seen this happen myself)
2015-11-29 8:59 GMT+01:00 Dan Kenigsberg <danken@redhat.com>:
On Sat, Nov 28, 2015 at 08:10:06PM +0530, mad Engineer wrote:
hello all i am having strange network issue with vms that are running on centos 6.7 ovirt nodes.
I recently added one more ovirt node which is running centos6.7 and upgraded from centos6.5 to centos6.7 on all other nodes.
All VMs running on nodes with centos6.7 as host Operating system fail to reach network gateway,but if i reboot that same host to centos6.5 kernel everything works fine(with out changing any network configuration).
Initially i thought it as configuration issue but its there on all nodes.if i reboot to old kernel everything is working.
I am aware about ghost vlan0 issue in centos6.6 kernel.Not aware about any issue in centos6.7 Also all my servers are up to date.
All physical interfaces are in access mode VLAN connected to nexus 5k switches.
working kernel- 2.6.32-431.20.3.el6.x86_64
non working kernel- 2.6.32-573.8.1.el6.x86_64
Do you have the possibility to test with kernel-2.6.32-504.16.2.el6.x86_64 (it's in CentOS Vault now) ? What I have seen in our environment is that - regarding this problem - it is the latest correctly working kernel. There are clear signs of misbehaviours due to changes in the VLAN code between that kernel and the next one (2.6.32-504.23.4.el6.x86_64). Not always, it could also depend on the nic driver involved. Also take a look at https://bugs.centos.org/view.php?id=9467 and https://bugzilla.redhat.com/show_bug.cgi?id=1263561 .
Can you provide the topology of your VM network config (vlan, bond, bond options, bridge options)? Do you have an IP address on the bridge?
(I have not seen this happen myself)
Dan, did you see this https://www.mail-archive.com/users@ovirt.org/msg28561.html thread? We have seen this bug in oVirt (bond+VLAN+bridges) but also in simple KVM with VLAN+bridges and with plain servers using VLANS directly over nic. Therefore I think the topology is almost unrelated and the problem regards VLAN code. I would be very interested in https://bugzilla.redhat.com/show_bug.cgi?id=1264316 but public access is denied. Do you have access to it? I hope so. Best regards, Giorgio.
each vm has 4 nics connected to 4 different bridges which is connected to 4 different physical interface in access mode VLAN.No bonding between interfaces.I have IP assigned on "ovirtmgmt" bridge which is used for storage,migration,console and VM internet access.All interfaces are 10G with MTU 9000. During my test only change i made was booting to centos6.5 kernel. Facing another issue with PXE booting guest machines switching to old kernel fixes this too On Sun, Nov 29, 2015 at 1:29 PM, Dan Kenigsberg <danken@redhat.com> wrote:
On Sat, Nov 28, 2015 at 08:10:06PM +0530, mad Engineer wrote:
hello all i am having strange network issue with vms that are running on centos 6.7 ovirt nodes.
I recently added one more ovirt node which is running centos6.7 and upgraded from centos6.5 to centos6.7 on all other nodes.
All VMs running on nodes with centos6.7 as host Operating system fail to reach network gateway,but if i reboot that same host to centos6.5 kernel everything works fine(with out changing any network configuration).
Initially i thought it as configuration issue but its there on all nodes.if i reboot to old kernel everything is working.
I am aware about ghost vlan0 issue in centos6.6 kernel.Not aware about any issue in centos6.7 Also all my servers are up to date.
All physical interfaces are in access mode VLAN connected to nexus 5k switches.
working kernel- 2.6.32-431.20.3.el6.x86_64
non working kernel- 2.6.32-573.8.1.el6.x86_64
Can you provide the topology of your VM network config (vlan, bond, bond options, bridge options)? Do you have an IP address on the bridge?
(I have not seen this happen myself)
participants (3)
-
Dan Kenigsberg -
Giorgio Bersano -
mad Engineer