Hi,
I'm new here and I've started using QEMU when I've started playing with
Unetlab/EVE Network simulator.

I have some questions about compression and images with a compressed
backing file:

1) If I create a compressed qcow2 image A and then I create B with backing
file A, will B contents be compressed? If no, is it possible to have
compression enabled also on image B?

2) I have an uncompressed qcow2 image A and an image B created with backing
file A. Then I convert image A into C enabling compression (with qemu-img
convert -c). When you rebase an image, I've understood that qemu looks at
every changed block from source base to destination base and stores the
different blocks within the image you're rebasing. If I rebase B from A
(uncompressed) to C (compressed) will qemu compare A blocks of data with
uncompressed C blocks of data (thus not growing up B image) or will it find
the whole image as changed and store lots of changes within image B?

3) Is there a command that I can use to see if an image has compression
enabled? qemu-img info does not show that info

PS: Unetlab/Eve virtual environment uses qemu v2.4.0

Thank you in advance for any help, best regards
    Gianni Costanzi

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