[libvirt-users] getting oriented/networking

Boylan, Ross Ross.Boylan at ucsf.edu
Fri Mar 20 00:51:30 UTC 2015

I've been using virt-manager and kvm with a disk image (as in the raw bits) from a physical windows 7 machine.  Initial performance was dreadful, but improved as I switched to virtio and spice.  I've been running linux VM's somewhat longer (much longer if you count kvm without libvirt).

There are lots of choices exposed by virt-manager.  How do I find out what the choices mean, and which are good ones?  This was true for the video (resolved by following instructions for spice, though I still wonder what the other settings are for), disks and the network.

In particular, I have a choice of lots of interfaces for my network; I picked eth1:macvtap because I wanted to bridge eth1.  But there is a "Source Mode" which I left at VEPA, even though Bridged was another choice.  But the bridge would already seem implicit in picking a source device of eth1:macvtap.  I don't know what "source mode" means.  The choices in the GUI seem like some of the options listed under forward on http://libvirt.org/formatnetwork.html; is that a good place to look for clarification.

I started a 2nd VM that also used eth1:macvtap (with virtio) and it had almost no network throughput.  So maybe I should use some other method?  I notice the network manager connection gui allows creation of bridges on the network; should I be using that?

I have been reading documentation, but I haven't found either a task-oriented discussion ("to get a windows machine working well, use these options" or "follow these steps") or an easy way to go from the choices in the GUI to a discussion of their meaning.

Thanks for any help you can offer.
Ross Boylan

More information about the libvirt-users mailing list