Glossary

Flavor: Predefined resource profile for instances (number of vCPUs, RAM, local system disk). Examples: m1.small, m1.large.

Floating IP: Publicly accessible IP address that can be assigned to an instance as needed. This keeps the internal network topology unchanged.

Home Region: The region automatically assigned to a user during registration.

Image: Operating system image from which new instances are launched. bwCloud-OS provides various preconfigured images (e.g., Debian 12, Ubuntu 24.04); custom images can also be uploaded.

Instance / VM: Virtual machine running in a region. It receives CPU, RAM, network, and storage resources and behaves like a physical server.

Project / Group Project: Administrative container for resources, users, and quotas. In a group project, multiple people share all instances, images, security groups, etc., equally.

Quota: Resource limit (vCPUs, RAM, volumes, etc.) per project. Increases can be requested via a support ticket.

Region: One of the four operational sites (Freiburg, Karlsruhe, Mannheim, Ulm). Each region is an independent OpenStack cluster with its own IP address logic.

Security Group: Set of firewall rules (inbound/outbound) assigned to an instance. By default, only SSH (port 22) is open; additional ports must be explicitly allowed.

Snapshot: Point-in-time copy of an instance or volume. Snapshots appear as images and can be downloaded or converted into new volumes/instances.

Volume (Block Storage): Persistent storage in bwCloud-OS that exists independently of a VM. Volumes can be attached to instances, resized, exported as images, or backed up via snapshots.