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LIC 3.4/RHEL63 : problems with live migration RRS feed

  • Question

  • I just installed the new LIC 3.4 on a RHEL 6.3 (kernel 2.6.32-279.el6.x86_64) without a problem, but I have noticed a network connectivity loss after a live migration in a Hyper-V 2008 R2 Cluster.

    After the migration the VM is not reachable, from an initial analysis seems to be an ARP related issue.

    In the same scenario RHEL62/LIC3.3 works fine.

    Has anyone had a similar problem?

    Tuesday, September 11, 2012 5:27 PM

Answers

  • The issue is caused by an RHEL 6.3 kernel bug that handles incorrectly GARP messages after live migration (more datails at https://bugzilla.redhat.com/show_bug.cgi?id=875309)

    Workaround:

    Edit the file, /etc/sysctl.conf and insert the following line:

    net.ipv4.conf.default.arp_notify = 1

    then reboot.

    RedHat will fix the bug in RHEL 6.4 (kernel 2.6.32-347.el6), actually in beta.


    Saturday, December 8, 2012 11:54 AM

All replies

  • Hi,

    are you sure that the MAC address of your VM is set to static? Otherwise it got a new MAC address after the LIVE migration.

    Regards,

    Hermann Maurer

    Wednesday, September 12, 2012 8:35 AM
  • I have IP address and MAC address both in static mode.

    My configuration:

    * A two-node cluster with an interface in trunk mode for VM traffic
    * A Cisco switch for connectivity

    Before the migration I see the VM MAC Address on the switch port in use by the first Hyper-V cluster node;
    After the migration the VM MAC address incorrectly remains on this switch port;
    At this time, connecting through Hyper-V console to the VM, I can repair the connection simply making any traffic (a ping is sufficient);
    After this operation I see the VM MAC address correctly moved on the switch port in use by the second Hyper-V cluster node.

    with RHEL62/LIC3.3 in the same scenario (same Hyper-V cluster, same switch, same network config on the VM, static MAC, static IP) all work fine, the MAC address moves immediately after live migration.

    Any ideas?



    Wednesday, September 12, 2012 3:07 PM
  • The issue is caused by an RHEL 6.3 kernel bug that handles incorrectly GARP messages after live migration (more datails at https://bugzilla.redhat.com/show_bug.cgi?id=875309)

    Workaround:

    Edit the file, /etc/sysctl.conf and insert the following line:

    net.ipv4.conf.default.arp_notify = 1

    then reboot.

    RedHat will fix the bug in RHEL 6.4 (kernel 2.6.32-347.el6), actually in beta.


    Saturday, December 8, 2012 11:54 AM