Re: Running qemu guest in background

[Ottavio Caruso]

On Sat, 16 May 2020 at 15:22, Mahmood Naderan <address@hidden> wrote:
>
> >qemu-system-xxxxxx  -nographic &
> >
> >However, there's a lot of other work you need to do if you then want
> >to communicate with console, serial port, monitor, etc.
>
>
>
>
> No that doesn't work.
> As soon as I press enter, I see
>
>
>
> [1]+ Stopped  qemu-system-x86_84 .....
>
>
> And I see the terminal prompt. As I grep for qemu process, I see that with 
> the state "TL"
> However, anydesk won't connect.

I've tried this from a script and it works. Pay attention to the command line:

$ cat boot-freebsd-virtio
#!/bin/sh
qemu-system-x86_64 \
-drive if=virtio,file=/home/oc/VM/img/freebsd.image,index=0,media=disk \
-drive if=virtio,file=/home/oc/VM/img/freebsd.image.old,index=1,media=disk \
-M q35,accel=kvm -m 250M -cpu host -smp $(nproc) \
-nic user,hostfwd=tcp::6664-:22,model=virtio-net-pci \
-display none -daemonize -pidfile pidfile.txt

$ ./boot-freebsd-virtio
$ jobs
[nothing]

[wait 20 seconds until sshd has started in the guest]

$ ssh 127.0.0.1 -p 6664
Password for oc@FreeBSD:
Last login: Sat May 16 18:00:25 2020 from 10.0.2.2
FreeBSD 12.1-RELEASE-p3 GENERIC

[shutdown the guest]
oc@FreeBSD:~ %             doas shutdown -p now
*** FINAL System shutdown message from oc@FreeBSD ***

System going down IMMEDIATELY



System shutdown time has arrived
Connection to 127.0.0.1 closed by remote host.
Connection to 127.0.0.1 closed.

[wait a few seconds]

$ ps aux|grep qemu
oc       12416  0.0  0.0  14896   956 pts/1    S+   18:04   0:00 grep
--color=auto qemu

[nothing in there]

[
In case the guest hangs and qemu is still running, you can get the pid
from pidfile.txt:
$ cat pidfile.txt
12383

$ kill 12383
]

So, there is a way to run qemu in the background without using
additional software. The line above works from a script but not from
the command line in interactive mode.


Be careful not to kill a VM if the root filesystem is  still mounted.
You might want to redirect -serial and -monitor to a Unix socket. I
have never tried it myself, though.


-- 
Ottavio Caruso