| SYSTEMD-MSTACK(1) | systemd-mstack | SYSTEMD-MSTACK(1) |
.SH "NAME" systemd-mstack, mount.mstack - Mstack Discoverable Disk
Images (DDIs)
.SH "SYNOPSIS"
.HP 360u
systemd-mstack [OPTIONS...] IMAGE
.HP 360u
systemd-mstack [OPTIONS...] [--mount] IMAGE PATH
.HP 360u
systemd-mstack [OPTIONS...] [--umount] PATH
.SH "DESCRIPTION"
.PP systemd-mstack is a tool for introspecting and interacting with
.mstack/ mount stack directories, as described in systemd.mstack(7).
It supports three different operations:
.PP The systemd-mstack command may be invoked as mount.mstack
in which case it implements the mount(8) "external helper"
interface. This ensures mount stack directories compatible with
systemd-mstack can be mounted directly by mount and
fstab(5). For details see below.
.PP In place of the image path a .v/ versioned directory may be specified,
see systemd.v(7) for details.
.SH "COMMANDS"
.PP 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.
.PP --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 mount(8) via a
command such as mount -t mstack mystack.mstack targetdir/, as well as
in fstab(5). For details, see below.
Added in version 260.
.RE
.PP -M
This is a shortcut for --mount --mkdir.
Added in version 260.
.RE
.PP --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
Added in version 260.
.RE
.PP -U
This is a shortcut for --umount --rmdir.
Added in version 260.
.RE
.PP -h, --help
Print a short help text and exit.
.RE
.PP --version
Print a short version string and exit.
.RE
.SH "OPTIONS"
.PP The following options are understood:
.PP --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.
Added in version 260.
.RE
.PP --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.
Added in version 260.
.RE
.PP --rmdir
If combined with --umount the specified directory where the mount
stack is mounted is removed after unmounting it.
Added in version 260.
.RE
.PP --image-policy=policy
Takes an image policy string as argument, as per
systemd.image-policy(7). The policy is enforced when operating on the
disk image specified via --image=, see above. If not specified,
defaults to the * policy, i.e. all recognized file systems in the image are
used.
.RE
.PP --image-filter=filter
Takes an image filter string as argument, as per
systemd.image-filter(7). The filter is taken into consideration when
operating on the disk image specified via --image=, see above. If not
specified no filtering is applied.
.RE
.PP --no-pager
Do not pipe output into a pager.
.RE
.PP --no-legend
Do not print the legend, i.e. column headers and the footer with hints.
.RE
.PP --json=MODE
Shows output formatted as JSON. Expects one of short (for the shortest
possible output without any redundant whitespace or line breaks), pretty
(for a pretty version of the same, with indentation and line breaks) or off
(to turn off JSON output, the default).
.RE
.SH "EXIT STATUS"
.PP On success, 0 is returned, a non-zero failure code otherwise.
.SH "INVOCATION AS /SBIN/MOUNT.MSTACK"
.PP The systemd-mstack executable may be symlinked to
/sbin/mount.mstack. If invoked through that it implements mount(8)'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/
.PP in a fashion mostly equivalent to:
# systemd-mstack --mount mystack.mstack targetdir/
.PP Note that since a single mount stack may contain multiple mount points it
should later be unmounted with umount -R targetdir/, for recursive
operation.
.PP 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
.PP When invoked this way the mount options ro, rw map to the corresponding
options listed above (i.e. --read-only).
.SH "SEE ALSO"
.PP systemd(1), systemd.mstack(7), systemd-nspawn(1),
systemd.exec(5), mount(8), umount(8)
| systemd 262.2 |