We are experiencing some packet loss between xen machines which we haven't seen before. Is this a problem anyone's run into before and/or has ideas on how to diagnose the issue?
The setup is CentOS 5 xen-3.0.3-80.el5_3.3
Aaron
what evidence do you have of packet loss? between the net and the machines or between machines bridged together with xen?
Pinging from one domU other domUs shows dropped packets, which is how we initially discovered something odd was going on. It also happens pinging to the domUs from other physical machines.
netstat -i in dom0 shows dropped packets (TX-DRP) on the vif devices. Within the domUs it comes back with zeros.
It only seems to happen under fairly heavy load.
The machines in question are on the same bridge xen. That bridge has separate subnets and one domU is a router that routes between them (and performs LVS functions).
Aaron
On Mon, 26 Sep 2011 14:08:47 -0500, Nehemiah wrote:
what evidence do you have of packet loss?
between the net and the machines or between machines bridged together with xen?
-- Nehemiah I. Dacres Saint Louis University:
Advanced Technology Group
Linux System Administrator Sent with
Sparrow [3]
On Monday, September 26, 2011 at 12:53 PM, Aaron Linnen
wrote:
We are experiencing some packet loss between xen machines
which we haven't seen before. Is this a problem anyone's run into before and/or has ideas on how to diagnose the issue?
The setup is
CentOS 5 xen-3.0.3-80.el5_3.3
Aaron
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Does dmesg show anything suspicious that might for example point to an overflowing connection tracking table or something similar?
Regards, Dennis
On 09/26/2011 10:17 PM, Aaron Linnen wrote:
Pinging from one domU other domUs shows dropped packets, which is how we initially discovered something odd was going on. It also happens pinging to the domUs from other physical machines.
netstat -i in dom0 shows dropped packets (TX-DRP) on the vif devices. Within the domUs it comes back with zeros.
It only seems to happen under fairly heavy load.
The machines in question are on the same bridge xen. That bridge has separate subnets and one domU is a router that routes between them (and performs LVS functions).
Aaron
On Mon, 26 Sep 2011 14:08:47 -0500, Nehemiah wrote:
what evidence do you have of packet loss? between the net and the machines or between machines bridged together with xen?
-- Nehemiah I. Dacres Saint Louis University: Advanced Technology Group Linux System Administrator Sent with Sparrow http://www.sparrowmailapp.com/?sig
On Monday, September 26, 2011 at 12:53 PM, Aaron Linnen wrote:
We are experiencing some packet loss between xen machines which we haven't seen before. Is this a problem anyone's run into before and/or has ideas on how to diagnose the issue?
The setup is CentOS 5 xen-3.0.3-80.el5_3.3
Aaron
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Unfortunately no, not on dom0 nor on the domU that is the router (that one did hit the conntrack limit not too long ago, so it was one of the first things we checked). Checked dmsg and /var/log/messages on all of the domUs and didn't see anything network or hardware related.
Aaron
On Mon, 26 Sep 2011 22:54:55 +0200, Dennis Jacobfeuerborn wrote:
Does dmesg show anything suspicious that might for example
point to an
overflowing connection tracking table or something
similar?
Regards, Dennis
On 09/26/2011 10:17 PM, Aaron
Linnen wrote:
Pinging from one domU other domUs shows dropped
packets, which is how we initially discovered something odd was going on. It also happens pinging to the domUs from other physical machines. netstat -i in dom0 shows dropped packets (TX-DRP) on the vif devices. Within the domUs it comes back with zeros. It only seems to happen under fairly heavy load. The machines in question are on the same bridge xen. That bridge has separate subnets and one domU is a router that routes between them (and performs LVS functions). Aaron On Mon, 26 Sep 2011 14:08:47 -0500, Nehemiah wrote:
what evidence do you have of
packet loss? between the net and the machines or between machines bridged together with xen? -- Nehemiah I. Dacres Saint Louis University: Advanced Technology Group Linux System Administrator Sent with Sparrow On Monday, September 26, 2011 at 12:53 PM, Aaron Linnen wrote:
We are experiencing some packet loss between xen machines which we
haven't seen before. Is this a problem anyone's run into before and/or has ideas on how to diagnose the issue? The setup is CentOS 5 xen-3.0.3-80.el5_3.3 Aaron _______________________________________________ CentOS-virt mailing list CentOS-virt@centos.org [1] CentOS-virt@centos.org> http://lists.centos.org/mailman/listinfo/centos-virt [2]
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Links: ------ [1] mailto:CentOS-virt@centos.org [2] http://lists.centos.org/mailman/listinfo/centos-virt [3] http://www.sparrowmailapp.com/?sig [4] mailto:CentOS-virt@centos.org [5] http://lists.centos.org/mailman/listinfo/centos-virt [6] mailto:CentOS-virt@centos.org [7] http://lists.centos.org/mailman/listinfo/centos-virt
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Aaron Linnen -
Dennis Jacobfeuerborn -
Nehemiah