[lvs-users] kernel panic with kernel 3.14.70, LVS on keepalived restart
netdev at bof.de
Tue May 24 16:44:13 BST 2016
Dear LVS users / netdev readers,
today I've got a pretty peculiar problem.
I've been running 3.14.48 (and some earlier 3.14 kernels) for a long time now
in an LVS / keepalived driven loadbalancing cluster. See below for more detail
on the setup.
Today I started to upgrade to the current 3.14.70 kernel. At first glance
everything seems fine, I can failover _to_ the box with the new kernel, and
traffic is flowing fine.
However, when I then switch BACK to a different box, the 3.14.70 kernel
crashes. I've got an incomplete console dump (IPMI avi capture, single
frame...) you can see here:
I usually manually failover by (having some automation) fiddle with
keepalived.conf VRRP priority settings, then restart the daemon.
The issue / reboot only manifests when I RESTART the ACTIVE keepalived. It
always happens, then, with 3.14.70. That never happened before.
On the other hand just reloading keepalived, with the prio-modified config,
As I don't remember why I restarted instead of reloading, I can for now change
my automation easily - but the issue is weird anyway.
More info on the setup:
1) kernel is vanilla 3.14.70 (and was vanilla 3.14.48 without the issue), with
a single (self written) patch to bonding applied (see
http://permalink.gmane.org/gmane.linux.network/316758). Unfortunately I cannot
live without that patch, i.e. can't try to reproduce with a pure vanilla
2) keepalived is 1.2.13
3) config uses "use_vmac" / "vmac_xmit_base", on multiple interfaces, i.e.
MACVLAN interfaces on top of:
4) "normal" interfaces are both bridge-over-VLAN-over-LACP-bond-over-eth and
5) there is active conntracking including conntrackd (but excluding LVS
state), LVS loadbalancing of some 15k pps, LVS sync, and heavy iptables use
including ipset matching, going on. Just for completeness.
Anybody got any idea what the root cause might be?
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