Bug 767567 - Define ifcfg alias on KVM guest crashes host
Summary: Define ifcfg alias on KVM guest crashes host
Keywords:
Status: CLOSED WORKSFORME
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: kvm
Version: 5.7
Hardware: x86_64
OS: Linux
unspecified
high
Target Milestone: rc
: ---
Assignee: jason wang
QA Contact: Virtualization Bugs
URL:
Whiteboard:
Depends On:
Blocks: 807971
TreeView+ depends on / blocked
 
Reported: 2011-12-14 11:24 UTC by wvc
Modified: 2012-04-18 13:22 UTC (History)
7 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2012-04-18 13:22:51 UTC
Target Upstream Version:


Attachments (Terms of Use)

Description wvc 2011-12-14 11:24:17 UTC
Description of problem:

When i define a network interface alias on a guest machine, the host crashes with a kernel panic. The host interface is configured as a bridge.


How reproducible:


Steps to Reproduce:

Start host and configure a network bridge.
Add the network bridge as to the client as a virtio nic.
Start the client and create an alias under /etc/sysconfig/network-scripts/ifcfg-eth0:0
restart the client's network service

  
Actual results:

kernel panic on the host machine


Expected results:

should simply work


Additional info:

My setup runs RHEL 5.7 on the host side and RHEL 6.1 on the client side. Both are x68_64 kernels.

Comment 1 wvc 2011-12-15 08:38:17 UTC
I have now tested assigning a second NIC to the guest bound to the same bridge. This works for a few hours but eventually results in a kernel panic as well

Comment 2 jason wang 2011-12-15 09:46:11 UTC
Hello:

If possible, would you please provide the panic information of host?

Thanks

Comment 3 wvc 2011-12-15 09:59:04 UTC
As this is our main production machine and Kdump was inactive at the time of the crash, i'm not able to supply you with any details. I've now enabled Kdump and i'll try to give you a the info tomorrow when employees have finished working.

Comment 4 Li, ZhenHua 2012-02-21 07:28:39 UTC
Could you please show the command line you start your vm?

Comment 5 wvc 2012-02-21 11:30:59 UTC
Sorry guys. I have now enabled Kdumping, but as it's a production machine that runs practically our complete network, it's very hard to bring it down.
I have added the 2nd nic through the graphical interface. I use the same bridge for both interfaces and both are installed as virtio adaptors.
virsh dumpxml provides this:

    <interface type='bridge'>
      <mac address='54:52:00:70:d2:63'/>
      <source bridge='br1'/>
      <model type='virtio'/>
    </interface>
    <interface type='bridge'>
      <mac address='54:52:00:67:82:98'/>
      <source bridge='br1'/>
      <model type='virtio'/>
    </interface>

I tried it before with just one adaptor and than added the alias to the guest itself, but then it crashes even faster. Now it kept running for about an hour before going into kernel panic.

Comment 6 RHEL Program Management 2012-04-02 10:53:14 UTC
This request was evaluated by Red Hat Product Management for inclusion
in a Red Hat Enterprise Linux release.  Product Management has
requested further review of this request by Red Hat Engineering, for
potential inclusion in a Red Hat Enterprise Linux release for currently
deployed products.  This request is not yet committed for inclusion in
a release.

Comment 7 Ronen Hod 2012-04-10 11:35:48 UTC
Dear customer,

Thank you for taking the time to enter a bug report with us. We do appreciate the feedback and look to use reports such as this to guide our efforts at improving our products. That being said, this bug tracking system is not a mechanism for getting support, and as such we are not able to make any guarantees as to the timeliness or suitability of a resolution.
 
If this issue is critical or in any way time sensitive, please raise a ticket through your regular Red Hat support channels to make certain that it gets the proper attention and prioritization to assure a timely resolution. 
 
For information on how to contact the Red Hat production support team, please see:
https://www.redhat.com/support/process/production/#howto

Thanks, Ronen.

Comment 8 juzhang 2012-04-17 08:19:45 UTC
Can not reproduce on rhel5.8 GA host with rhel6.1 guest. would you please check my steps? and would you please provide qemu-kvm commandline by ps -aux | grep qemu-kvm when boot guest? thanks

 host info:
  # uname -r
  2.6.18-308.el5
  # rpm -qa|grep kvm
  kvm-83-249.el5

guest(rhel6.1) info:
# uname -r
2.6.32-131.0.15.el6.x86_64


1.boot guest with below command line
/usr/libexec/qemu-kvm -usbdevice tablet -rtc-td-hack -name 6.1 -smp 2 -m
4G -uuid 9e6f04cf-2ad7-45aa-9333-2d2ee26570c6 -boot dc -drive
file=/home/RHEL-Server-6.1-64.qcow2,if=virtio,cache=none,boot=on,format=qcow2,werror=stop
-net nic,vlan=1,macaddr=52:54:00:94:a3:8b,model=virtio -net
tap,vlan=1,script=/etc/qemu-ifup -notify all -balloon none -monitor
stdio -vnc :1

2. check existing NIC(eth0) in guest
cat /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=dhcp
HWADDR=52:54:00:94:A3:8B
#IPV6INIT="yes"
MTU=1500
#NM_CONTROLLED="yes"
ONBOOT=yes
TYPE=Ethernet
IPV6INIT=no
USERCTL=no

3. create an alias nic(eth0:0) for eth0 and special static IP address

cat /etc/sysconfig/network-scripts/ifcfg-eth0:0
DEVICE=eth0:0
IPADDR=192.169.0.101
#IPV6INIT="yes"
MTU=1500
#NM_CONTROLLED="yes"
ONBOOT=yes
TYPE=Ethernet
IPV6INIT=no
USERCTL=yes

3. restart network service in guest

    #service network restart

4.  check guest NIC interface

# ifconfig
  eth0      Link encap:Ethernet  HWaddr 52:54:00:94:A3:8B
           inet addr:10.66.11.217  Bcast:10.66.11.255  Mask:255.255.252.0
           inet6 addr: fe80::5054:ff:fe94:a38b/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:15288 errors:0 dropped:0 overruns:0 frame:0
           TX packets:3182 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:1000
           RX bytes:6943376 (6.6 MiB)  TX bytes:252689 (246.7 KiB)

   eth0:0    Link encap:Ethernet  HWaddr 52:54:00:94:A3:8B
           inet addr:192.169.0.101  Bcast:192.169.0.255  Mask:255.255.255.0
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

  result:
           host works well.

Comment 9 wvc 2012-04-17 08:28:31 UTC
My apologies, i should have posted this sooner, but after updating everything, it no works! We had some downtime last weekend so i took the opportunity to test this again and it worked straight away. I have no idea why it didn't at first. Back then i tried it 3 times, once with a 2nd virtual nic, twice with an alias on the host itself, and each time i received a kernel panic.
Now i recreated the virtual machine from scratch and it works.
Thanks for your efforts!

Comment 10 Ronen Hod 2012-04-18 13:22:51 UTC
Closing, since according to the previous comment, the problem disappeared and cannot be reproduced.


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