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<p>I have numerous qcow2 images which need to be reduced in size and
have their maximum size (virtual size) reduced. Physical disk
space became so low that VMs "auto-paused" themselves, I moved
enough images to solve the immediate problem but need to rectify
the underlying issue. It seems that qcow[2] files are grown in
size such that the data inside of them takes about 50-60% of the
space (does anyone know the actual algorithm or how to control
it?). Given the total physical disk space on the hypervisors, I
need something more restrictive.</p>
<p>Our hypervisors are a mix of Ubuntu 14 or 16 LTS (qemu-img 2.2 or
2.5). After doing all the preparation (defragment, reduce OS
partition size) "qemu-img resize" reports that shrinking isn't
supported yet. My web research indicates that, to accomplish
this, I have to:</p>
<blockquote>
<p> convert to raw</p>
<p> shrink the image</p>
<p>convert back to qcow[2]</p>
<p>increase the image size to provide for some growth</p>
</blockquote>
<p>I'm hoping I've missed something in my research and that someone
knows an easier way. I don't feel constrained to qemu-img but
this is a production environment precluding consideration of
experimental software. Virt-resize, guestfish or any other
reasonable option is fine with me. Solutions or ideas? Thanks.<br>
</p>
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