illumos gate

Snippet from the zoneadm manpage

       clone [-m copy] [-s zfs_snapshot] source_zone

           Install a zone by copying an existing installed zone. This
           subcommand is an alternative way to install the zone.

           -m copy

               Force the clone to be a copy, even if a "ZFS clone" is
               possible.

           -s zfs_snapshot

               Specify the name of a ZFS snapshot to use as the source of the
               clone. The snapshot must be a snapshot of the source zone taken
               from a previous "zoneadm clone" installation.

           The source zone must be halted before this subcommand can be used.

It looks like the '-m' option is not a generic option but brand specific, the manpage should probably be updated for this.
I was trying to use it but both the lx and ipkg brand on OmniOS do not support this flag.