[GLLUG] KVM Performance

[Mike Brodbelt]

On 09/06/2020 22:52, Ken Smith via GLLUG wrote:

> Indeed. So wouldn't passing a block device from the host through to the 
> guest minimise the 'components' that are 'in the way'
> 
> I can' t help thinking that there must be something more behind a drop 
> from 60MB/s to 15MB/s in write performance
> 
> I'd value your thoughts :-) Ken

Can't speak to your exact bottleneck here, but I think I'd try and 
eliminate your disk hardware from the game for a start, to see what 
happens there.

Try creating a null block device 
(https://www.kernel.org/doc/html/latest/block/null_blk.html), and then 
benchmark writes to that on the host and the guest. See what that does 
as a baseline....

Mike