[libvirt] Libvirtd needs to be always running/

[Daniel P. Berrange]

On Wed, Sep 03, 2008 at 07:55:20PM -0700, Yushu Yao wrote:
> Thanks Atsushi and Stefan,
> 
> It seems that libvirtd has to run with root, is this true?

Yes, because it has todo lots of privileged jobs, such as starting
QEMU with permissiong to use /dev/kvm,  accessing disks and logical
volumes in /dev, creating TAP devices, creating bridge devices,
and much more. That said, if you were to chmod/chown all the devices
in question, you could run libvirtd unprivileged - it requires alot
of setup ahead of time though.

> But why does libvirtd need to run for QEMU? If it's for start/stop/pause vm,
> is Qemu's command line tool not enough?

Libvirt does much more than just starting/stopping QEMU. It interacts
with its monitor console to control many aspects of it at runtime. It
also tracks state of running VMs to detect shutdown & cleanup, and
also manages storage, and networking state. 


Daniel
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