systemd systemd-mstack 1 systemd-mstack mount.mstack Mstack Discoverable Disk Images (DDIs) systemd-mstack OPTIONS IMAGE systemd-mstack OPTIONS --mount IMAGE PATH systemd-mstack OPTIONS --umount PATH systemd-mstack is a tool for introspecting and interacting with .mstack/ mount stack directories, as described in systemd.mstack7. It supports three different operations: Show general mount stack information, including all described overlayfs layers and bind mounts. Mount a mount stack to a local directory. Unmount a mount stack from a local directory. The systemd-mstack command may be invoked as mount.mstack in which case it implements the mount8 "external helper" interface. This ensures mount stack directories compatible with systemd-mstack can be mounted directly by mount and fstab5. For details see below. If neither of the command switches listed below are passed the specified mount stack is opened and general information about it is shown, including a list of all defined layers. --mount -m Mount the specified mount stack to the specified directory. To unmount a mount stack directory mounted like this use the --umount operation. Note that this functionality is also available in mount8 via a command such as mount -t mstack mystack.mstack targetdir/, as well as in fstab5. For details, see below. -M This is a shortcut for --mount --mkdir. --umount -u Unmount a mount stack from the specified directory. This command expects one argument: a directory where mount stack was mounted. All mounted mounts will be recursively unmounted -U This is a shortcut for --umount --rmdir. The following options are understood: --read-only -r Operate in read-only mode. By default, --mount will establish writable mount points. If this option is specified they are established in read-only mode instead. --mkdir If combined with --mount the directory to mount the mount stack to is created if it is missing. Note that the directory is not automatically removed when the mount stack is unmounted again. --rmdir If combined with --umount the specified directory where the mount stack is mounted is removed after unmounting it. On success, 0 is returned, a non-zero failure code otherwise. The systemd-mstack executable may be symlinked to /sbin/mount.mstack. If invoked through that it implements mount8's "external helper" interface for the (pseudo) file system type mstack. This means conformant mount stack directories may be mounted directly via # mount -t mstack mystack.mstack targetdir/ in a fashion mostly equivalent to: # systemd-mstack --mount mystack.mstack targetdir/ Note that since a single mount stack may contain multiple mount points it should later be unmounted with umount -R targetdir/, for recursive operation. This functionality is particularly useful to mount mount stacks automatically at boot via simple /etc/fstab entries. For example: /path/to/mystack.nspawn /images/mystack/ mstack defaults 0 0 When invoked this way the mount options ro, rw map to the corresponding options listed above (i.e. --read-only). systemd1 systemd.mstack7 systemd-nspawn1 systemd.exec5 mount8 umount8