Re: [Libguestfs] Can I specify qcow2 preallocation method with virt-builder?

On Tue, May 17, 2016 at 03:41:53PM +0100, Richard W.M. Jones wrote: > On Tue, May 17, 2016 at 05:15:57PM +0300, Yaniv Kaul wrote: > > When creating qcow2 images using virt-builder, is there a way to specify > > the qcow2 preallocation, as possible with qemu-img create -o > > preallocation=metada , for example? > > No .. but .. it does default to preallocation=metadata provided that > the output format is qcow2: > > https://github.com/libguestfs/libguestfs/blob/master/builder/builder.ml#L... I should say this only applies when the image needs to be resized (ie. you supply a --size parameter which != the size of the template), AND if the resize is the final step that the planner comes up with. https://rwmj.wordpress.com/2013/12/14/writing-a-planner-to-solve-a-tricky...

In the general case implementing this is more complicated. I think it would require another planner transition. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top