Planning for Availability Zone

Similar to host groups, availability zones are another way to create logical groupings of hosts. The IBM® Cloud Infrastructure Center also supports the standard OpenStack APIs for host groups and availability zones.

Overview

Availability zones are not created sepearately; rather, they are defined by attaching specific metadata information to a host group.

Virtual machines are kept within the Availability Zone A virtual machine can be deployed to a specific host or to a host group or to an availability zone. After deployment, if the virtual machine is migrated, it must always be migrated within the same availability zone as it is first created in.

Nova availability zone support for host groups When a virtual machine is deployed to a host group, the virtual machine's availability zone is the same as the host group's availability zone.

For more information, see Availability Zones.

Note: When migrating a virtual machine, the target list is unavailable if the virtual machine's host is the only host in its own availability zone.

On the Create Host Group page and Add Storage page of the WebUI, only the availability zone that has a host in it, is shown in the availability zone list.