- On Mitaka compute nodes, if you want to modify the default disk allocation
ratio of 1.0, you should set that on every compute node, rather than
setting it in the scheduler. This means the disk, RAM and CPU allocation
ratios now all work in the same way.
- For Liberty compute nodes, the disk_allocation_ratio works as before, you
must set it on the scheduler if you want to change it.
For Mitaka compute nodes, the disk_allocation_ratio set on the compute
nodes will be used only if the configuration is not set on the scheduler.
This is to allow, for backwards compatibility, the ability to still
override the disk allocation ratio by setting the configuration on the
In Newton, we plan to remove the ability to set the disk allocation ratio
on the scheduler, at which point the compute nodes will always define the
disk allocation ratio, and pass that up to the scheduler. None of this
changes the default disk allocation ratio of 1.0. This matches the
behaviour of the RAM and CPU allocation ratios.