On Wed, Jun 15, 2011 at 02:00:36PM +0100, Paul Mansfield wrote: > On 14/06/11 13:02, Richard W.M. Jones wrote: > > qcow2 uses a two-level directory. The second level is not allocated > > until required unless you selected the "preallocation" option when > > creating the disk. So if you didn't use "-o preallocation" then yes > > this overhead can grow as more disk blocks get allocated. By the way, > > we found that preallocation is faster. > > > > Mark wrote extensive documentation on qcow2 here: > > > > http://people.gnome.org/~markmc/qcow-image-format.html > > that's very helpful, thanks
BTW there's also preallocation=metadata option which preallocates just the directory. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into Xen guests. http://et.redhat.com/~rjones/virt-p2v _______________________________________________ virt-tools-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/virt-tools-list
