On 12/08/2018 16:34, Sad Clouds wrote:
OK, I cloned NetBSD VM, kept everything the same, but installed Debian
with XFS file system.
$ dd if=/dev/zero of=out bs=1M count=10000 conv=fsync
this gives 682 MB/sec which is what I would normally expect
Just dug into my IO settings a bit.
My NetBSD VM has 'Use Host IO cache' ticked and my ubuntu VM does not
although I did rerun the test with the box unticked on NetBSD and got
the same result. I am running all my virtual box tests on a Windows 10
host and nothing I can do is getting different performance results. I've
always turned off the use host io cache setting as its always seemed
silly to me to burn memory twice for disk IO caches.
So this is some sort of interaction between the way the NetBSD host does
IO and the linux host OS that the linux VM's don't hit.
Mike
