For now, at least, I'm stuck with an old version of qemu-kvm
qemu is set as cache=none
I see that in libvirt and I see that doing a ps on qemu-kvm.
Yet, using "vmtouch" I see that (where ID is the real instance ID), to the matching disk:
it's using 29 GB of cache!
Why would that be? I could ask vmtouch to pull it out of cache, but I'm concerned whatever put it there in the first place, will put it back later..
I see this issue on multiple compute notes in two environments., I don't see this issue on the third environment.
(I'm using OpenStack IceHouse and also see /var/lib/nova/instances/_base is being cached )
Unfortunately, with all the caching, we end up going to swap...as opposed to taking items out of cache.