howto control VM from outside (shutdown...)

howto control VM from outside (shutdown...)

[Paolo Pedaletti]

Ciao,

the question was posted here:
http://www.linux-kvm.com/content/daemonize-vs-monitor-commands

"The original post asked about gracefully shutting down KVM guest using
scripts"

When I shutdown the host machine, I want to
hibernate/shutdown/screendump/savevm/senkeys/system_powerdown(/migrate?)
also all the VM running (without using libvirt)

I could ssh to each VM and halt it, but does exist a better/cleaner
solution?

How can I communicate to kvm console?

thank you

-- 
/* Paolo Pedaletti,
 * paolo@pedaletti.it www.pedaletti.it */

Re: howto control VM from outside (shutdown...)

[David Mair]

Paolo Pedaletti wrote:
> Ciao,
> 
> the question was posted here:
> http://www.linux-kvm.com/content/daemonize-vs-monitor-commands
> 
> "The original post asked about gracefully shutting down KVM guest using
> scripts"
> 
> When I shutdown the host machine, I want to
> hibernate/shutdown/screendump/savevm/senkeys/system_powerdown(/migrate?)
> also all the VM running (without using libvirt)
> 
> I could ssh to each VM and halt it, but does exist a better/cleaner
> solution?
> 
> How can I communicate to kvm console?

Take a look at the qemu -monitor option. You can use it to re-direct the 
monitor console to a large number of character devices, including 
sockets. The settings are the same as for the -serial option. I've used 
it to access the monitor console from a telnet client.

-- 
David.

Re: howto control VM from outside (shutdown...)

[paolo pedaletti]

Ciao David,
thank you for the answer

> Take a look at the qemu -monitor option. You can use it to re-direct the
> monitor console to a large number of character devices, including
> sockets. The settings are the same as for the -serial option. I've used
> it to access the monitor console from a telnet client.

ok, I have found this:
http://www.linux-kvm.com/content/multiplexing-your-monitor-and-serial-port
http://www.linux-kvm.com/content/two-ways-access-your-virtual-machine-monitor-across-network

and it works, BUT ... why this command doesn't works:
echo -e "info name \n" | nc  127.0.0.1 4444
echo -e "info name \n" | nc  127.0.0.1 4445
neither:
echo "info name" | nc  127.0.0.1 4444
echo "info name" | nc  127.0.0.1 4445

(output:
��\x01��\x03����QEMU 0.9.1 monitor - type 'help' for more information
)

with this command line option:
	-monitor  telnet:127.0.0.1:4444,server,nowait \
	-serial mon:telnet:127.0.0.1:4445,server,nowait

?

-- 
Paolo Pedaletti

Re: howto control VM from outside (shutdown...)

[Alberto Treviño]

On Monday 19 January 2009 02:40:04 pm David Mair wrote:
> Take a look at the qemu -monitor option. You can use it to re-direct the
> monitor console to a large number of character devices, including
> sockets. The settings are the same as for the -serial option. I've used
> it to access the monitor console from a telnet client.

I use the the telnet option:

  -monitor telnet::[port],server,nowait

For interactive control I use telnet:

  $ telnet localhost [port]

and I can connect to it to run any commands I want.  Just be aware that you 
should exit with Ctrl-C or by making sure you are at the telnet prompt when 
you issue quit.  If you issue quit to the VM, the entire VM will shutdown 
very, very quickly and ungracefully.

To send commands through a script, I use netcat:

  echo "system_powerdown" | netcat -T -c localhost [port]

I also have a PHP script that opens a socket connection to the telnet port, 
sends the command, and parses the output for errors.  I'll be happy to share 
it.  Let me know if you want it.

Re: howto control VM from outside (shutdown...)

[Paolo Pedaletti]

ciao Alberto,

>   -monitor telnet::[port],server,nowait

ok

> For interactive control I use telnet:
>   $ telnet localhost [port]

ok, it works, thank you

> To send commands through a script, I use netcat:
>   echo "system_powerdown" | netcat -T -c localhost [port]

no, it doesn't work :-(

$ while : ; do echo "info name" | netcat -T lowdelay -C  \
	127.0.0.1 10101  ; sleep 1 ; done

��\x01��\x03����QEMU 0.9.1 monitor - type 'help' for more information
(qemu) info name��\x01��\x03����QEMU 0.9.1 monitor - type 'help' for more
information
(qemu) info name��\x01��\x03����QEMU 0.9.1 monitor - type 'help' for more
information
(qemu) info name��\x01��\x03����QEMU 0.9.1 monitor - type 'help' for more
information
(qemu) info name��\x01��\x03����QEMU 0.9.1 monitor - type 'help' for more
information
(qemu) info name��\x01��\x03����QEMU 0.9.1 monitor - type 'help' for more
information
(qemu) info name��\x01��\x03����QEMU 0.9.1 monitor - type 'help' for more
information
(qemu) info name��\x01��\x03����QEMU 0.9.1 monitor - type 'help' for more
information

command line: (kvm-82, ubuntu 8.10 2.6.27-9-server x86_64)
/usr/local/bin/qemu-system-x86_64 -name marco \
	-vnc :10 -monitor telnet:127.0.0.1:10101,server,nowait \
	-cpu qemu64 -m 512 -smp 1 -vga std \
	-drive file=/dev/mapper/vm-vm_marco,if=virtio,cache=off,boot=on\ 	-k it
-usb -usbdevice tablet -localtime -daemonize \
	-net nic,vlan=1,model=e1000,macaddr=52:10:11:01:01:01 \
	-net vde,vlan=1,sock=/var/run/vde2/kvm1_vde.ctl \
	-net nic,vlan=2,model=virtio,macaddr=52:10:11:02:01:01 \
	-net vde,vlan=2,sock=/var/run/vde2/kvm2_vde.ctl \
	-pidfile /home/vm/marco/marco.pid

do you know/understand why it doesn't works for me?

> I also have a PHP script that opens a socket connection to the telnet port, 
> sends the command, and parses the output for errors.  I'll be happy to share 
> it.  Let me know if you want it.

yes, thank you.


-- 
/* Paolo Pedaletti,
 * paolo@pedaletti.it www.pedaletti.it */