[sheepdog-users] [sheepdog users] cluster snapshot VS qemu-img

[Liu Yuan]

On Mon, Aug 18, 2014 at 10:45:37AM +0200, Valerio Pachera wrote:
> I've been testing cluster snapshot with the new --multithread option.
> 
> converting the same vdi:
> 
> cluster snapshot --multithread
> time 4'14''
> dog cpu 42%
> sheep cpu 23%
> I/O nic input: 116Mbit/s
> 
> 
> qemu-img convert
> time 2'13''
> qemu-img cpu 20%
> sheep cpu 45%
> I/O nic input: 205Mbit/s
> Restore: 6'01''

We use only at most nr_of_nodes * 2 threads for snapshot save, considering not
draining the cluster too much.

I guess qemu-img use more threads and it doesn't calculating the fingerprint
to de-duplicate.

Thanks
Yuan