mount unit
also: .mount unit, mount service
A systemd unit file that defines how and where a filesystem or block device is mounted at boot time or on demand. Mount units have a .mount extension and replace traditional /etc/fstab entries.
A mount unit is a systemd configuration file (with a .mount extension) that describes the mounting of filesystems, network shares, or storage devices. Instead of editing /etc/fstab, modern Linux systems use mount units to specify mount points, device paths, mount options, and dependencies.
For example, a mount unit for an external USB drive might be stored at /etc/systemd/system/mnt-backup.mount and contain directives like What=/dev/sdb1, Where=/mnt/backup, and Type=ext4. Systemd then manages the mounting according to the unit's configuration.
Mount units integrate with systemd's dependency system, allowing you to specify that certain services should only start after a mount succeeds, or that the mount should be automatic at boot. You can enable, disable, start, and check status using standard systemd commands like systemctl enable and systemctl start.