[libvirt] Xen 4.1 misc issues

Roberto Sassu roberto.sassu at polito.it
Wed Sep 11 12:50:33 UTC 2013


Hi everyone

I'm using Ubuntu 12.04.3 LTS with the Xen hypervisor
installed (package version: 4.1.2-2ubuntu2.10),
and Libvirt v0.10.2.2 (that interacts with Xen through
the libxl driver).

I performed some adjustments to have the required
features:

  - Switch from Xend to libxl:
      I created upstart jobs for xenstored and xenconsoled
      so that necessary daemons are started earlier enough
      and Libvirt can contact the hypervisor through libxl.

  - Add support for Open vSwitch:
      I added the script 'vif-openvswitch', taken from
      the master branch of the GIT repository, to the
      /etc/xen/scripts directory in order to plug network
      interfaces to Open vSwitch switches.

I know that the support for libxl is experimental
in Xen 4.1, but I'm wondering if someone has a solution
to the following issues:

1) On domain destroy, the host configuration is not clean:
    if the flag 'force' is set to 0 some entries in the
    xenstored database are not removed (console, ...)
    if the flag 'force' is set to 1 (as it is done
    in Libvirt), the event 'online' associated to the
    network interface is not triggered and, thus, the
    vif is not removed from the Open vSwitch switch.
    To fix this issue, I temporarily added a call
    to vif-openvswitch into the xen-hotplug-cleanup script.

2) When a domain is started from Libvirt, the console
    source path does not appear in the output of the
    command 'virsh dumpxml instance-00000381'

3) Sometimes, a domU is not started at all. If I start
    a virtual machine from Libvirt through virsh or directly
    through xl, these tools report that the virtual machine
    is running but I see no messages coming from the console
    and the CPU time remains fixed.

I'm attaching some files that may be useful to understand
the problem:

  - libvirt.xml: domain specifications (Libvirt format)
  - domain.xl: domain specifications (Xen format)
  - libvirt_virsh_dumpxml.log: output of the command
    'virsh dumpxml instance-00000381'
  - xl_create.log: output of the command 'xl create -d domain.xl'
  - xl_info.log: output of the command 'xl info'
  - qemu-dm-instance-00000381.log: qemu-dm log
  - syslog_vif6_0.log: vif attach/detach logs from /var/log/syslog
  - xenstore-db-not-clean.log: xenstore db entries not removed
    after 'xl destroy'
  - libvirt_libxl.log: log from /var/log/libvirt/libxl.log
    after the execution of the command 'virsh create libvirt.xml'

Lastly, I want to add that the image I'm using for the tests
is Ubuntu Precise 12.04.3 LTS, taken from the URL:

http://cloud-images.ubuntu.com/precise/current/precise-server-cloudimg-amd64-disk1.img

and the kernel is taken from the URL:

http://cloud-images.ubuntu.com/precise/current/unpacked/precise-server-cloudimg-amd64-vmlinuz-virtual


Thanks

Roberto Sassu
-------------- next part --------------
A non-text attachment was scrubbed...
Name: libvirt.xml
Type: text/xml
Size: 1070 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20130911/7b2131f8/attachment-0001.xml>
-------------- next part --------------
name = "instance-00000381"
uuid = "a65c782d-05fe-4c54-9911-8e7e4cb33244"
maxmem = 512
memory = 512
vcpus = 1
kernel = "/var/lib/nova/instances/instance-00000381/kernel"
extra = "ro root=/dev/xvda1"
localtime = 0
on_poweroff = "destroy"
on_reboot = "restart"
on_crash = "destroy"
vfb = [ "type=vnc,vncunused=1,vnclisten=node-110,keymap=en-us" ]
disk = [ "tap:raw:/var/lib/nova/instances/instance-00000381/disk,xvda,w" ]
vif = [ "mac=fa:16:3e:55:5d:e0,bridge=br-tvd-91970,script=vif-bridge" ]

-------------- next part --------------
A non-text attachment was scrubbed...
Name: libvirt_virsh_dumpxml.log
Type: text/x-log
Size: 1558 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20130911/7b2131f8/attachment-0006.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: xl_create.log
Type: text/x-log
Size: 1958 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20130911/7b2131f8/attachment-0007.bin>
-------------- next part --------------
host                   : node-110
release                : 3.2.0-40-ima
version                : #64 SMP Tue Apr 9 14:21:15 CEST 2013
machine                : x86_64
nr_cpus                : 2
nr_nodes               : 1
cores_per_socket       : 2
threads_per_core       : 1
cpu_mhz                : 2128
hw_caps                : bfebfbff:20100800:00000000:00000940:0000e3bd:00000000:00000001:00000000
virt_caps              : hvm
total_memory           : 2023
free_memory            : 151
free_cpus              : 0
xen_major              : 4
xen_minor              : 1
xen_extra              : .2
xen_caps               : xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p hvm-3.0-x86_64 
xen_scheduler          : credit
xen_pagesize           : 4096
platform_params        : virt_start=0xffff800000000000
xen_changeset          : unavailable
xen_commandline        : placeholder
cc_compiler            : gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) 
cc_compile_by          : roberto.sassu
cc_compile_domain      : polito.it
cc_compile_date        : Fri Jul 26 11:33:14 CEST 2013
xend_config_format     : 4
-------------- next part --------------
A non-text attachment was scrubbed...
Name: qemu-dm-instance-00000381.log
Type: text/x-log
Size: 313 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20130911/7b2131f8/attachment-0008.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: syslog_vif6_0.log
Type: text/x-log
Size: 2151 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20130911/7b2131f8/attachment-0009.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: xenstore-db-not-clean.log
Type: text/x-log
Size: 1669 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20130911/7b2131f8/attachment-0010.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: libvirt_libxl.log
Type: text/x-log
Size: 6433 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20130911/7b2131f8/attachment-0011.bin>


More information about the libvir-list mailing list