Ubuntu 11.04 : how to use qemu-monitor command through virsh command

You may sometimes want to use qemu-monitor command through virsh.

Here’s an explanation of how to use qemu-monitor command.

Seen from the man manual of virsh , using qemu-monitor-command w/ virsh is discouraged.

# man virsh QEMU-SPECIFIC COMMANDS       NOTE: Use of the following commands is strongly discouraged.  They can       cause libvirt to become confused and do the wrong thing on subsequent       operations.  Once you have used this command, please do not report       problems to the libvirt developers; the reports will be ignored.       qemu-monitor-command domain command optional --hmp           Send an arbitrary monitor command command to domain domain through           the qemu monitor.  The results of the command will be printed on           stdout.  If --hmp is passed, the command is considered to be a           human monitor command and libvirt will automatically convert it           into QMP if needed.  In that case the result will also be converted           back from QMP.

[ How to use ]

start a VM (SL6-vm1)

# virsh start SL6-vm1 # LANG=C virsh list --all | grep running 21 SL6-vm1              running

usage : virsh qemu-monitor-command –hmp domain ‘commnad’

About qemu-monitor command , please see http://en.wikibooks.org/wiki/QEMU/Monitor ,

Or you can check what kind of commands you can use like this:

# virsh qemu-monitor-command --hmp SL6-vm1 'help' # virsh qemu-monitor-command --hmp SL6-vm1 'info'

show network info of SL6-vm1

# virsh qemu-monitor-command --hmp SL6-vm1 'info network' Devices not on any VLAN:  hostnet0: fd=19 peer=net0  net0: model=virtio-net-pci,macaddr=52:54:00:11:18:f1 peer=hostnet0

You can also use qemu-monitor command by stopping libvirt-bin and then connecting to a monitor socket with netcat. However when you stop libvrit-bin , you will not use virsh command , so I would not recommend this way.

# /etc/init.d/libvirt-bin stop # LANG=C virsh start SL6-vm1 error: unable to connect to '/var/run/libvirt/libvirt-sock', libvirtd may need to be started: No such file or directory error: failed to connect to the hypervisor

# /etc/init.d/libvirt-bin start # LANG=C virsh start SL6-vm1 Domain SL6-vm1 started # /etc/init.d/libvirt-bin stop # nc -U /var/lib/libvirt/qemu/SL6-vm1.monitor QEMU 0.14.0 monitor - type 'help' for more information (qemu) info network info network Devices not on any VLAN:  hostnet0: fd=18 peer=net0  net0: model=virtio-net-pci,macaddr=52:54:00:11:18:f1 peer=hostnet0 (qemu) # LANG=C virsh list --all error: unable to connect to '/var/run/libvirt/libvirt-sock', libvirtd may need to be started: No such file or directory error: failed to connect to the hypervisor