[libvirt] [PATCH libvirt 2/2] storage: learn to create qcow2 with preallocation

[Marc-André Lureau]

Hi

On Wed, May 9, 2012 at 1:33 PM, Christophe Fergeau <cfergeau at redhat.com> wrote:
> Big speed difference during win7 installations? or are you thinking of
> another big difference? sparse/non-sparse allocation can make a big

I guess it's mostly speed up in any appending write IO (20G for
win7..). Which occurs rather often, especially on new systems.
Overall, the VM feels much faster, but that's my pov.

> difference on disk usage, which is a big diference as well imo.

Indeed, but in case of sparse, the disk space failure is enough to
guarantee that the image is created, whether it is sparse or not. So,
from an image creation operation, it is equal, assuming there is no
other difference than disk usage

> I agree with you that erroring out is better, but I tend to prefer
> consistency in cases like this.

I don't think it's the same, in one case we are talking about resource
usage, in the other case we are talking about VM tweak / io speed-up.

-- 
Marc-André Lureau