Disksid

Disksid is a general term used in computing to refer to an identifier assigned to a disk or disk image to uniquely identify it within a system, across operations, and in automation tasks. The concept is not a single standardized specification but a family of approaches used by operating systems, hypervisors, and cloud platforms to reference storage devices.

In practice, a disksid can be derived from hardware-provided serial numbers, GUIDs assigned by partitioning schemes, or virtualization-layer identifiers. Common examples include disk serial numbers exposed by SCSI and SATA interfaces and GPT disk GUIDs, as well as filesystem UUIDs used by Linux and other operating systems. Some environments also rely on persistent names such as /dev/disk/by-id in Linux or cloud-provider IDs for attached volumes.

Benefits include stable references in scripts, configuration files, and backups, enabling devices to be recognized after reboots or hardware changes. Disksid-based references are often used in fstab entries, backup tools, cluster configurations, and virtualization templates to maintain consistent access to storage.

Limitations include changes when disks are replaced, repartitioned, or re-attached to different hosts; swapping controllers, cloning disks, or migrating across environments can require updates to the mapping or metadata that preserves the association.

Related concepts include UUIDs, disk by-id naming schemes, GPT disk GUIDs, and LUN identifiers, all of which serve to provide persistent identification of storage devices across reboots and hardware changes.