daily-notes

gistfile1.txt

Since Linux 2.6.15 it is possible to mark a mount and its
       submounts as shared, private, slave or unbindable. A shared mount
       provides the ability to create mirrors of that mount such that
       mounts and unmounts within any of the mirrors propagate to the
       other mirror. A slave mount receives propagation from its master,
       but not vice versa. A private mount carries no propagation
       abilities. An unbindable mount is a private mount which cannot be
       cloned through a bind operation. The detailed semantics are
       documented in Documentation/filesystems/sharedsubtree.txt file in
       the kernel source tree; see also mount_namespaces(7).