Chapter 2. Environment Requirements and Assumptions
In order to enable Instance HA, your Red Hat OpenStack Platform overcloud must meet the following requirements:
- The environment was deployed using Red Hat OpenStack Platform director. See Director Installation and Usage for details.
- Fencing has already manually been enabled on the control plane.
The following packages are installed on all nodes:
- The environment can tolerate a full outage of both Compute and Control planes.
- Shared storage is enabled within the environment for ephemeral and block storage. See Section 2.1, “Exceptions for Shared Storage” for related information.
The Message Broker (AMQP) recognizes each Compute node’s hostname as valid. To check the hostname of a Compute node:
heat-admin@compute-n $ sudo crudini --get /etc/nova/nova.conf DEFAULT host
Each Compute node should be able to reach the endpoint set in $OS_AUTH_URL. In addition, this environment variable must be set to either:
- The overcloud’s authentication service (which requires access to the external network), or
- The internal authentication URL.
When Instance HA is enabled, overcloud upgrade or scale-up operations are not possible. Any attempts to do so will fail. This includes both minor and major upgrades.
Before upgrading or scaling your overcloud, disable Instance HA first. For instructions, see Chapter 5, Rollback.