On Mon, May 12, 2014 at 11:53 AM, Eric Blake <ebl...@redhat.com> wrote: > Ah, but it is: > > $ qemu-img create -f qcow2 -o help > Supported options: > size Virtual disk size > compat Compatibility level (0.10 or 1.1) > backing_file File name of a base image > backing_fmt Image format of the base image > encryption Encrypt the image > cluster_size qcow2 cluster size > preallocation Preallocation mode (allowed values: off, metadata) > lazy_refcounts Postpone refcount updates > > and more importantly, it only appears in the help output of -f modes > that actually support a backing file. Contrast: > > $ qemu-img create -f raw -o help > Supported options: > size Virtual disk size
This is much more prominent in the top-level help: rebase [-q] [-f fmt] [-t cache] [-p] [-u] -b backing_file [-F backing_fmt] filename
