[pve-devel] qcow2 bench and speed optimisations

[Alexandre DERUMIER]

>>Above command only pre-allocates metadata, so creation is still fast?
Yes, it's creating the file in second

>>If so, we can do that by default, because metadata is small (128MB/TB).
Note that the size file is the full size of the disk (no sparse file). 
	




	


----- Mail original ----- 

De: "Dietmar Maurer" <dietmar at proxmox.com> 
À: "Alexandre DERUMIER" <aderumier at odiso.com>, pve-devel at pve.proxmox.com 
Envoyé: Vendredi 14 Septembre 2012 07:10:42 
Objet: RE: [pve-devel] qcow2 bench and speed optimisations 

> 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