Ubuntu Manpage: lxc-copy - copy an existing container.

NAME

       lxc-copy - copy an existing container.

SYNOPSIS

       lxc-copy {-n, --name name} [-P, --lxcpath path] {-N, --newname newname} [-p, --newpath newpath] [-B,
                --backingstorage backingstorage] [-s, --snapshot] [-a, --allowrunning] [-K, --keepname] [-D,
                --keepdata] [-M, --keepmac] [-L, --fssize size [unit]] [-- hook arguments]
       lxc-copy {-n, --name name} [-P, --lxcpath path] [-N, --newname newname] [-p, --newpath newpath] {-e,
                --ephemeral} [-B, --backingstorage backingstorage] [-s, --snapshot] [-a, --allowrunning] [-K,
                --keepname] [-D, --keepdata] [-M, --keepmac] [-L, --fssize size [unit]] [-- hook arguments]
       lxc-copy {-n, --name name} [-P, --lxcpath path] [-N, --newname newname] [-p, --newpath newpath] {-e,
                --ephemeral} [-B, --backingstorage backingstorage] [-s, --snapshot] [-t, --tmpfs] [-K,
                --keepname] [-M, --keepmac] [-- hook arguments]
       lxc-copy {-n, --name name} [-P, --lxcpath path] {-N, --newname newname} [-p, --newpath newpath] {-R,
                --rename}

DESCRIPTION

lxc-copy creates and optionally starts (ephemeral or non-ephemeral) copies of existing containers.

lxc-copy creates copies of existing containers. Copies can be complete clones of the original container.
In this case the whole root filesystem of the container is simply copied to the new container. Or they
can be snapshots, i.e. small copy-on-write copies of the original container. In this case the specified
backing storage for the copy must support snapshots. This currently includes btrfs, lvm (lvm devices do
not support snapshots of snapshots.), overlay, and zfs.

The copy's backing storage will be of the same type as the original container. overlay snapshots of di‐
rectory backed containers are exempted from this rule.

When the -e flag is specified an ephemeral snapshot of the original container is created and started.
Ephemeral containers will have lxc.ephemeral = 1 set in their config file and will be destroyed on shut‐
down. When -e is used in combination with -D a non-ephemeral snapshot of the original container is creat‐
ed and started. Ephemeral containers can also be placed on a tmpfs with -t flag. NOTE: If an ephemeral
container that is placed on a tmpfs is rebooted all changes made to it will currently be lost!

When -e is specified and no newname is given via -N a random name for the snapshot will be chosen.

Containers created and started with -e can have custom mounts. These are specified with the -m flag. Cur‐
rently two types of mounts are supported: bind, and overlay. Mount types are specified as suboptions to
the -m flag and can be specified multiple times separated by commas. overlay mounts are currently speci‐
fied in the format -m overlay=/src:/dest. When no destination dest is specified dest will be identical to
src. Read-only bind mounts are specified -m bind=/src:/dest:ro and read-write bind mounts -m
bind=/src:/dest:rw. Read-write bind mounts are the default and rw can be missing when a read-write mount
is wanted. When dest is missing dest will be identical to src. An example for multiple mounts would be -m
bind=/src1:/dest1:ro,bind=/src2:ro,overlay=/src3:/dest3.

The mounts, their options, and formats supported via the -m flag are subject to change.

OPTIONS

-N,--newname newname
The name for the copy.

-p,--newpath newpath
The path for the copy.

-R,--rename
Rename the original container.

-s,--snapshot
Create a snapshot of the original container. The backing storage for the copy must support snap‐
shots. This currently includes btrfs, lvm, overlay, and zfs.

-a,--allowrunning
Allow the creation of a Snapshot of an already running container. This may cause data corruption
or data loss depending on the used filesystem and applications. Use with care.

-F,--foreground
Run the snapshot in the foreground. The snapshots console will be attached to the current tty.
(This option can only be specified in conjunction with -e.)

-d, --daemon
Run the snapshot as a daemon (This is the default mode for ephemeral containers.). As the contain‐
er has no more tty, if an error occurs nothing will be displayed, the log file can be used to
check the error. (This option can only be specified in conjunction with -e.)

-m, --mount mounttype
Specify a mount for a snapshot The opts argument for the mount type can by of type {bind, over‐
lay}. For example -m bind=/src:/dest:ro,overlay=/src:/dest (This option can currently only be
specified in conjunction with -e.).

-t, --tmpfs
When this option is specified the ephemeral container will be placed on a tmpfs. NOTE: Rebooting
an ephemeral container that is located on a tmpfs will currently cause all changes made to it to
be lost. This flag will only work for ephemeral containers created with the -e flag. The original
container, from which the ephemeral snapshot is created, must be stored as a simple directory.

-B, --backingstorage backingstorage
Specify the backing storage type to be used for the copy where 'backingstorage' is of type
'btrfs', 'dir', 'lvm', 'loop', 'overlay', or 'zfs'.

-L, --fssize size [unit]
Specify the size for an 'lvm' filesystem.

-K, --keepname
When this option is specified the hostname of the original container will be kept for the copy.

-D, --keepdata
When this option is specified with -e a non-ephemeral container is created and started.

-M, --keepmac
When this option is specified the MAC address of the original container will be kept for the copy.

COPY HOOK

       If  the container being copied has one or more lxc.hook.clone specified, then the specified hooks will be
       called for the new container. The first 3 arguments passed to the clone hook will be the container  name,
       a  section ('lxc'), and the hook type ('clone'). Extra arguments passed to lxc-copy will be passed to the
       hook program starting at argument 4. The LXC_ROOTFS_MOUNT environment variable gives the path under which
       the container's root filesystem is mounted. The configuration file pathname is stored in LXC_CONFIG_FILE,
       the new container name in LXC_NAME, the old container name in LXC_SRC_NAME, and the  path  or  device  on
       which the rootfs is located is in LXC_ROOTFS_PATH.

COMMON OPTIONS

       These options are common to most of lxc commands.

       -?, -h, --help
              Print a longer usage message than normal.

       --usage
              Give the usage message

       -q, --quiet
              mute on

       -P, --lxcpath=PATH
              Use an alternate container path. The default is /var/lib/lxc.

       -o, --logfile=FILE
              Output to an alternate log FILE. The default is no log.

       -l, --logpriority=LEVEL
              Set  log priority to LEVEL. The default log priority is ERROR. Possible values are : FATAL, ALERT,
              CRIT, WARN, ERROR, NOTICE, INFO, DEBUG, TRACE.

              Note that this option is setting the priority of the events log in the alternate log file.  It  do
              not have effect on the ERROR events log on stderr.

       -n, --name=NAME
              Use container identifier NAME.  The container identifier format is an alphanumeric string.

       --rcfile=FILE
              Specify  the  configuration file to configure the virtualization and isolation functionalities for
              the container.

              This configuration file if present will be used even if there  is  already  a  configuration  file
              present in the previously created container (via lxc-create).

       --version
              Show the version number.

AUTHOR

       Christian Brauner <christian.brauner@mailbox.org>

                                                   2025-05-10                                        lxc-copy(1)