Set CPU Allocation Ratio For Host Aggregate

Problem

It is desired to over-provision CPU cores on a subset of hosts instead of provisioning it for the OpenStack environment as a whole. A CPU allocation ratio parameter may be set as metadata for a particular host aggregate containing that subset of hosts.

Environment

• Platform9 Managed OpenStack - v3.11 and Lower
• Nova

Prerequisites

• AggregateCoreFilter must be set in /etc/nova/nova.conf on the Management Plane.

Note: If you're uncertain if this is set, submit a ticket to Platform9 Support to check and have it enabled.

Procedure

1. Navigate to the "Infrastructure" tab in Clarity UI.
2. Select the "Host Aggregates" tab.
3. Select the host aggregate you intend to modify (assuming one has already been created).
4. Click "Edit Host Aggregate".
5. In the Metadata section, select "Add key-value metadata".
6. Specify the Key as cpu_allocation_ratio and the Value as the intended ratio, e.g. 2.0.

Screen_Shot_2019-10-31_at_5.06.42_PM.png

7. Click "Save".

Additional Information

OpenStack Docs: Overcommitting CPU and RAM