Hi All,
One of our developers managed to trigger a kernel oops on a 4.4.2 dom0.. Oops text is attached. He was working on setting up network namespaces / bridging inside a centos domU, had activated the bridge and lost networking (probably config error) so he rebooted the VM. On reboot is when we saw the oops, along with various xen procs hanging:
rootÂÂÂÂ 23388Â 0.0Â 1.6 132796 32264 ?ÂÂÂÂÂÂÂ SLsl Oct02ÂÂ 0:04 /usr/sbin/xl create /mnt/xen/gx/xen/metrixc7
rootÂÂÂÂ 26119Â 0.0Â 0.0ÂÂÂÂÂ 0ÂÂÂÂ 0 ?ÂÂÂÂÂÂÂ ZÂÂÂ Oct02Â Â0:00Â \_ [block] <defunct>
rootÂÂÂÂ 26127Â 0.0Â 0.0ÂÂÂÂÂ 0ÂÂÂÂ 0 ?ÂÂÂÂÂÂÂ ZÂÂÂ Oct02ÂÂ 0:00Â \_ [block] <defunct>
rootÂÂÂÂ 26137Â 0.0Â 0.0ÂÂÂÂÂ 0ÂÂÂÂ 0 ?ÂÂÂÂÂÂÂ ZÂÂÂ Oct02ÂÂ 0:00Â \_ [block] <defunct>
rootÂÂÂÂ 26157Â 0.0Â 0.0ÂÂÂÂÂ 0ÂÂÂÂ 0 ?ÂÂÂÂÂÂÂ ZÂÂÂ Oct02ÂÂ 0:00Â \_ [block] <defunct>
rootÂÂÂÂ 26169Â 0.0Â 0.0ÂÂÂÂÂ 0ÂÂÂÂ 0 ?ÂÂÂÂÂÂÂ ZÂÂÂ Oct02ÂÂ 0:00Â \_ [block] <defunct>
rootÂÂÂÂ 26195Â 0.0Â 0.0ÂÂÂÂÂ 0ÂÂÂÂ 0 ?ÂÂÂÂÂÂÂ ZÂÂÂ Oct02ÂÂ 0:00Â \_ [vif-bridge] <defunct>
rootÂÂÂÂ 24625Â 0.0Â 0.0ÂÂÂÂÂ 0ÂÂÂÂ 0 ?ÂÂÂÂ ÂÂÂDsÂÂ Oct02ÂÂ 0:06 [tapdisk]
At this point the dom0 is still up and running existing VMs fine, I can also migrate live VMs off of it successfully although the post-migration clean up fails and hangs:
libxl: error: libxl_device.c:935:device_backend_callback: unable to remove device with path /local/domain/0/backend/vbd/17/51712
Host is running centos 7 with the 4.4.2-7 package and kernel 3.10.68-11.el6.centos.alt.x86_64. I've also attached xl dmesg.
First time I've seen anything like this and not sure if his networking/bridging in the domU is related or just coincidental. Any thoughts / ideas? Haven't been able to reproduce with some subsequent tests.
- Nathan
