[virt-tools-list] Storage image files and permissions

Joachim Wagner jwagner at computing.dcu.ie
Tue Nov 27 15:23:31 UTC 2018


> > > Moreover, I created a QCOW3 disk image. I asked for a maximum capacity
> > > of 6GB and initial allocation of 0GB (zero).
> > > I got a 6GB image file. Is this a bug or am I missing something?
> 
> Any hint on this?
> With QCOW2 I used to get a 200KB file as initial image, no matter it's
> maximum size.

Have you checked the space used on disk or the file size? Possibly, the 
default on your system is to use sparse pre-allocation when supported by the 
filesystem. Also, did you try preallocation=off or metadata (see man page)?

How do you request qcow3? According to the edit history of https://
wiki.qemu.org/Features/Qcow3 , qcow3 should be many years old but the manpage 
of qemu-img on my current system does not mention qcow3.

Joachim





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