is a group of nodes that is as isolated as possible from other nodes (separate servers, network, power, even geography). The ring guarantees that every replica is stored in a separate zone. To increase capacity in our environment, we can add an extra zone, to which data will then replicate. In this example, we will add an extra storage node, with its second disk,
/dev/sdb, used for our OpenStack Storage. This node makes up the only node in this zone.
To add additional capacity to existing zones, we repeat the instructions for each existing zone in our cluster. For example, the following steps assume zone 5 (
z5) doesn't exist, so this gets created when we build the rings. To simply add additional capacity to existing zones, ...