[pve-devel] switch to deadline scheduler by default

[Stefan Priebe - Profihost AG]

Am 16.03.2012 07:40, schrieb Dietmar Maurer:
>>> recommandations for kvm and cfq for best performance are
>>>
>>> /sys/block/device/queue/iosched/quantum = 32
>>> /sys/block/device/queue/iosched/slice_idle = 0
>>>
>>> Maybe can add them somewhere ?

Sorry to get into this discussion but why can't we use the deadline
scheduler?

We can leave the general kernel scheduler on CFQ and then add a patch
which sets deadline for each block device in the kernel (not sure if
possible). Or we can do this with a small tuning package like redhad
does with it's storage profile. It would just be a small script which
executes at the end of runlevel 2.

for i in /sys/block/*/queue/scheduler; do
  echo deadline >$i 2>/dev/null
done

Greets
Stefan