On 05/02/2018 10:13 AM, Max Reitz wrote:
We also recently added 'qemu-img measure', which DOES report how many
clusters are in use. Is any of that reusable here?
It only tells you that information for a hypothetical new image, though,
doesn't it?
It has two uses: with just a size, estimate the overhead needed to
create a file with the given format and exposing the given size to the
guest (both sparse and fully allocated sizes are estimated); and with a
pre-existing image, compute the exact overhead needed for 'qemu-img
convert' to create a new image with the given format and the same
guest-visible contents. The latter use, where it uses an existing guest
image as the starting point to measure, indeed only tells you what a
hypothetical new image will occupy (the used cluster count, not the
wr_highest_offset count) - but isn't that what you want?
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
