Btw, regarding QEMU: QEMU gets requests _after_ sorting by the guest's
elevator, then submits them to the host's elevator. If the guest and
host elevators are both configured 'anticipatory', do the anticipatory
delays add up?
Anticipatory is non-work-conserving. If the data is going to end passing thru host's deadline scheduler, probably it is better to the guest with deadline or maybe even no-op since it doesn't really know anything about the real
disk locations of the data.
-- Greetz, Antonio Vargas aka winden of rgba^ntw^bg