VMid

VMid, short for Virtual Machine Identifier, is a label used to uniquely identify a virtual machine within a virtualization environment. The exact meaning and behavior of a VMid vary by platform, but it generally refers to a persistent identifier assigned to a VM by the hypervisor or management layer. In many systems, a VMid is a UUID or similarly structured token intended to distinguish one virtual machine from another across operations and management actions.

Persistence and storage are platform-dependent. A VMid is commonly stored in the VM’s configuration data, management database, or a related metadata store. It is typically designed to survive reboots and certain hardware migrations, though some operations—such as cloning, re-importing, or significant reconfiguration—may result in a new identifier being assigned.

Usage and implications for administration include inventory tracking, lifecycle management, auditing, and integration with orchestration tools. Because a VMid is separate from human-friendly names or network identifiers, it helps manage large fleets of VMs reliably even when hosts or hostnames change. Operators often rely on VMids in logs and API calls to correlate actions across systems.

Relation to other identifiers varies by platform. VMid is distinct from a VM’s name, IP address, or MAC address and is more stable than those attributes. Different virtualization ecosystems use different terms for the same concept: some platforms refer to it as a VM UUID, instance UUID, VM GUID, or domain UUID. Understanding the local platform’s naming helps ensure correct identification and correlation of virtual machines.