voldid

Voldid is a term used in some contexts to refer to the unique identifier associated with a storage volume managed by the Android Volume Daemon (vold). Vold is the legacy background service responsible for mounting, unmounting, and tracking external storage such as SD cards and USB storage on Android devices, particularly in older Android versions. The voldid conceptually represents an identifier that distinguishes one volume from another so the system can manage multiple volumes correctly.

In the typical vold configuration, including legacy vold.fstab files, each declared volume is linked to a specific mount point and a set of mount options. The voldid serves as the persistent reference that the daemon uses to locate the appropriate device when it is connected, and to maintain a stable mapping between the physical storage and its mounted path. Applications and system components interact with the mounted filesystem path, while the underlying voldid helps the storage subsystem keep track of which device corresponds to which mount.

The term is largely historical and context-specific. Modern Android storage management has shifted toward newer components such as the StorageManager service, and official documentation no longer emphasizes voldid in everyday use. In contemporary Linux and embedded systems, the broader concept related to voldid is commonly described as a volume ID or filesystem UUID, which serves the same general purpose: providing a stable, device-independent identifier for a storage volume to support reliable mounting and data management.