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Diffstat (limited to 'man/systemd-nspawn.xml')
| -rw-r--r-- | man/systemd-nspawn.xml | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/man/systemd-nspawn.xml b/man/systemd-nspawn.xml index 88b5758d91..3a2af2711c 100644 --- a/man/systemd-nspawn.xml +++ b/man/systemd-nspawn.xml @@ -565,6 +565,52 @@ </varlistentry> <varlistentry> + <term><option>--overlay=</option></term> + <term><option>--overlay-ro=</option></term> + + <listitem><para>Combine multiple directory trees into one + overlay file system and mount it into the container. Takes a + list of colon-separated paths to the directory trees to + combine and the destination mount point.</para> + + <para>If three or more paths are specified, then the last + specified path is the destination mount point in the + container, all paths specified before refer to directory trees + on the host and are combined in the specified order into one + overlay file system. The left-most path is hence the lowest + directory tree, the second-to-last path the highest directory + tree in the stacking order. If <option>--overlay-ro=</option> + is used instead of <option>--overlay=</option> a read-only + overlay file system is created. If a writable overlay file + system is created all changes made to it are written to the + highest directory tree in the stacking order, i.e. the + second-to-last specified.</para> + + <para>If only two paths are specified, then the second + specified path is used both as the top-level directory tree in + the stacking order as seen from the host, as well as the mount + point for the overlay file system in the container. At least + two paths have to be specified.</para> + + <para>For details about overlay file systems, see <ulink + url="https://www.kernel.org/doc/Documentation/filesystems/overlayfs.txt">overlayfs.txt</ulink>. Note + that the semantics of overlay file systems are substantially + different from normal file systems, in particular regarding + reported device and inode information. Device and inode + information may change for a file while it is being written + to, and processes might see out-of-date versions of files at + times. Note that this switch automatically derives the + <literal>workdir=</literal> mount option for the overlay file + system from the top-level directory tree, making it a sibling + of it. It is hence essential that the top-level directory tree + is not a mount point itself (since the working directory must + be on the same file system as the top-most directory + tree). Also note that the <literal>lowerdir=</literal> mount + option receives the paths to stack in the opposite order of + this switch.</para></listitem> + </varlistentry> + + <varlistentry> <term><option>--setenv=</option></term> <listitem><para>Specifies an environment variable assignment |