Interface MountPoint

If there are non-critical errors while extracting metadata, those errors may be added to this field.

The type of file system on the volume, like ext4, apfs, or ntfs.

Note: on Windows this may show as "ntfs" for remote filesystems, as that is how the filesystem is presented to the OS.

Whether the volume is mounted read-only.

Examples of read-only volumes include the macOS APFS system snapshot at /, mounted ISO images, and write-protected media.

Note that the macOS root volume (/) UUID changes on every OS update, so consumers should avoid using it for persistent identification.

Indicates if this volume is primarily for system use (e.g., swap, snap loopbacks, EFI boot, or only system directories).

On macOS, the sealed APFS system snapshot at / is detected natively via MNT_SNAPSHOT; other infrastructure volumes under /System/Volumes/* are detected via APFS volume roles (IOKit). Note that /System/Volumes/Data is not a system volume — it holds all user data, accessed via firmlinks.

Mount location (like "/" or "C:"). Explicit Linux path queries may return a file path when that file is itself a bind-mount target. Public volume enumeration omits detected non-directory targets; unprobed remote targets are retained when skipNetworkVolumes is true.

Lightweight accessibility status observed while enumerating the mount point. This does not run a filesystem integrity check such as fsck or diskutil verifyVolume.

Linux and macOS derive this from bounded access probes. Windows additionally maps explicit offline network errors to disconnected. The status may be absent when probing is deliberately skipped, such as for an unprobed remote mount.

Not every value is a VolumeHealthStatus: on Linux, a non-critical metadata error may land here instead, such as "Blkid warning: …" when libblkid cannot read a volume's UUID or label.

On btrfs, the subvolume path this mount exposes, taken verbatim from the subvol= mount option (e.g. /@ or /@home). Undefined on non-btrfs volumes.

Several mount points can be distinct subvolumes of one btrfs filesystem and therefore share a single filesystem-level VolumeMetadata.uuid. subvol and subvolid distinguish such siblings. Note that the subvol path changes if the subvolume is renamed or moved; for a rename-stable identifier prefer VolumeMetadata.subvolumeUuid.

On btrfs, the numeric subvolume id from the subvolid= mount option (e.g. 256, 257). Undefined on non-btrfs volumes.

Stable across remount/reboot on a given filesystem, but not unique across filesystems and not preserved by btrfs send/receive. See subvol for context and VolumeMetadata.subvolumeUuid for a stronger identifier.

The APFS volume role, if available. Only present on macOS for APFS volumes.

Common roles: "System", "Data", "VM", "Preboot", "Recovery", "Update", "Hardware", "xART", "Prelogin", "Backup".

Used for system volume detection: volumes with a non-"Data" role and MNT_DONTBROWSE are classified as system volumes.