nova/releasenotes/notes/update-initial-allocation-defaults-94106033b66b8fa0.yaml
Sean Mooney 1260cdd492 update default overcommit
This change updates the cpu and ram initial
allocation ratios to 4.0 and 1.0 to reflect
the typical values that are suitable for non web
hosting workloads.

Change-Id: I283eb270a4e47da15cf01d098b4f3952f7b5b570
implements: bp/nova-change-default-overcommit-values
2022-10-06 12:50:56 +01:00

22 lines
1.1 KiB
YAML

---
upgrade:
- |
In this release the default values for the initial ram and cpu allocation
ratios have been updated to 1.0 and 4.0 respectively. This will not
affect any existing compute node resource providers but the new default
will take effect on the creation of new resource providers.
other:
- |
The default initial allocation ratios enabled ram over commit by default
with a factor of ``1.5``. This value was chosen early in nova's history
as the predominant workload was web hosting or other light weight
virtualization. Similarly the default initial cpu allocation ratio
defaulted to 16. As more demanding workload from telco, enterprise,
scientific and governmental users became the norm the initial values we
had chosen became less and less correct overtime. These have now been
updated to reflect a more reasonable default for the majority of our users.
As of this release the initial ram allocation value is 1.0 disabling
overcommit by default for new compute nodes and the initial cpu allocation
ratio is now 4.0 which is a more reasonable overcommit for non idle
workloads.