[pve-devel] qcow2 bench and speed optimisations

Dietmar Maurer dietmar at proxmox.com
Fri Sep 14 07:10:42 CEST 2012


> 4)qemu-img create -f qcow2 -o
> size=10000000000,preallocation=metadata,compat=1.1,lazy_refcounts=on
> file.img
> So I think it should be great to add an option for preallocatting metadatas,
> the boost is really huge.

Above command only pre-allocates metadata, so creation is still fast?
If so, we can do that by default, because metadata is small (128MB/TB).

> Do you have any news about FVD ?

Well, I finally asked the developer if he can update the code to make it work
with current qemu, but got no answer then. I thing he is not willing to do that.

I also tried myself, but the code is simply too old, so it would require much
work to get that working (maybe several weeks?).

- Dietmar






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