15.8. Configuring the cell availability zone
You must assign each cell to an availability zone to ensure that instances created on the Compute nodes in that cell are only migrated to other Compute nodes in the same cell. Migrating instances between cells is not supported.
The Controller cell must be in a different availability zone from the Compute cells.
You can use host aggregates to configure the availability zone for the Compute cell. The following example shows the command to create a host aggregate for the cell
cell1, define the availability zone for the host aggregate, and add the Compute nodes within the cell to the availability zone:
(undercloud)$ source ~/overcloudrc (overcloud)$ openstack aggregate create --zone cell1 cell1 (overcloud)$ openstack aggregate add host cell1 hostA (overcloud)$ openstack aggregate add host cell1 hostB
You cannot use the
OS::TripleO::Services::NovaAZConfigparameter to automatically create the AZ during deployment, because the cell is not created at this stage.
- Migrating instances between cells is not supported. To move an instance to a different cell, you must delete it from the old cell and re-create it in the new cell.
For more information on host aggregates and availability zones, see Creating and managing host aggregates.