Red Hat Bugzilla – Bug 720347
RHEL 6.1 Xen paravirt guest is getting network outage during live migration (host side)
Last modified: 2012-02-20 22:44:29 EST
See bug 713585. This BZ tracks the host side changes.
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
Patch(es) available in kernel-2.6.18-282.el5 You can download this test kernel (or newer) from http://people.redhat.com/jwilson/el5 Detailed testing feedback is always welcomed.
I reproduced the bug with kernel version 2.6.18-275.el5. Then update the guest kernel to 2.6.18-300.el5 with xen-3.0.3-135.el5 and do the test for 20 times (host: i386 and x86_64, intel and amd). Verify with the 6.2 pv guest(i386 and x86_64, 2.6.32-220.el6).There are only little packets (1~2 packets) lost during the live migration. It is acceptable. So change this bug to VERIFIED. Bug verify steps: 1. Start nfs in hostA and mount the nfs to hostB. #mount $hostA_ip:/root/img /root/img 2. Modify the xen config file and restart xend service. Boot up the pv guest. Edit "/etc/xen/xend-config.sxp" on these two machines as following: (xend-relocation-server yes) (xend-relocation-port 8002) (xend-relocation-address '') (xend-relocation-hosts-allow '') # service xend restart # xm cr pv-config.cfg For RHEL6.2 PV guest, login to modify parameters. Set net.ipv4.conf.{all,default,IFACE}.arp_notify to 1 as following: #sysctl net.ipv4.conf.all.arp_notify = 1 #sysctl net.ipv4.conf.default.arp_notify = 1 #sysctl net.ipv4.conf.lo.arp_notify = 1 #sysctl net.ipv4.conf.eth0.arp_notify = 1 3. Ping the guest from the other machine. $ ping $guest_ip 4. Live migrate the guest between hostA and hostB. # xm migrate -l pv-guest $hostA_ip # xm migrate -l pv-guest $hostB_ip 5. Check the ping results after live migration finish. 6. Redo step3 to step5 for 20 times.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHSA-2012-0150.html