Glossary

This page defines the terms used across vMetal documentation. Other pages link here instead of redefining these terms.

vMetal is the Machine provisioning and lifecycle layer behind vCluster Platform. It covers both physical and virtual Machines across multiple infrastructure drivers. This site documents the Metal3 driver in depth today.

Core terms

Term	Definition
vMetal	The Machine provisioning and lifecycle layer behind vCluster Platform.
Machine	vMetal's claim on one server, physical or virtual. A Machine's identity spans from request to deletion, and doesn't outlive the claim. Once deleted, the server it claimed returns to its capacity pool for reuse by a later Machine. See Machine concept.
Server	The physical or virtual host a Machine claims, such as a BareMetalHost under the Metal3 driver. A server's identity persists independently of any single Machine. It exists before being claimed, and continues to exist, cleaned and available, after the Machine that claimed it is deleted.
NodeClaim	The Kubernetes resource that implements a Machine request and tracks its lifecycle. See Configuration.
Driver	An infrastructure path that vMetal provisions Machines through, such as Metal3 for bare metal. The NodeProvider API also defines other provider types. This site currently documents the Metal3 path in depth. See the configuration schema reference.
Machine type (also called node type, NodeType)	An administrator-published offering that groups eligible servers by label selector and sets their provisioning defaults, such as OS image, SSH keys, network configuration, and cost. Tenants request capacity by machine type, not by individual server. See Resource hierarchy.
Capacity pool	The set of servers eligible for a given machine type at a point in time. A machine type becomes unavailable when its capacity pool is exhausted.
Private Nodes	The vCluster feature that attaches dedicated Machines to a tenant cluster as Kubernetes nodes. See Cluster attachment for how vMetal servers join a tenant cluster, and vCluster Private Nodes for the full feature.
Auto Nodes	A vCluster feature that requests and maintains a target count of Private Nodes automatically. See vCluster Auto Nodes.

Access model

Platform administrators configure NodeProvider and NodeType resources. Tenants request Machines within the scope their project role and quotas allow. For the full role and permission model, see Security and project isolation.

BMC and BCM are not the same thing

These two acronyms are easy to confuse and refer to unrelated systems.

Acronym	Full name	What it is
BMC	Baseboard Management Controller	The out-of-band management interface on a physical server that Metal3 and Ironic use to power-cycle, inspect, and reimage hardware. See BMC credential management.
BCM	NVIDIA Base Command Manager	A separate NodeProvider driver for clusters managed through NVIDIA's cluster management product. It is unrelated to baseboard management controllers.