[fedora-virt] Disk device performance in F11

Richard W.M. Jones rjones at redhat.com
Wed Jul 1 08:37:51 UTC 2009

On Tue, Jun 30, 2009 at 02:09:17PM -0600, Jerry James wrote:
> On Tue, Jun 30, 2009 at 12:31 AM, Dor Laor <dlaor at redhat.com> wrote:
> > It might be due to different image caching defaults.
> > Can you grab the current command line of qemu and change -drive file=xxxx,..,cache=writeback and retest?
> As far as I can tell, virt-manager doesn't use the -drive option, but
> just passes the name of the hard disk image as the last command line
> argument.

I don't think this is correct.

> The virt-manager concept seems nice, but I abandoned it after using it
> for only a short time in F-10 because (a) it didn't give me an easy
> way to see what options it ultimately passed to qemu-kvm, and (b) it
> didn't give me a way to fiddle with nonstandard options.  It looks
> like I'm probably going to abandon it again in F-11 after only using
> it for a short time, for exactly the same reasons.

libvirt isn't just a wrapper around qemu-kvm, it drives half a dozen
different virtualization systems, giving you the benefit of
abstracting the details of the hypervisor from the management tools.
So for that reason we don't support tweaking the qemu command line
arbitrarily.  However if there are particular features of qemu or KVM
that you think we should support, please raise them.


Richard Jones, Emerging Technologies, Red Hat  http://et.redhat.com/~rjones
virt-top is 'top' for virtual machines.  Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.

More information about the Fedora-virt mailing list