dynamic /bin /sbin

[Matthew Dillon]

    I should add, the complexity of what I am proposing here is one of
    the reasons why such VFS layering *MUST* be implemented in userland.
    In order to support this as an efficient mechanism I intend to rewrite
    the VFS file/directory caching layer to allow the kernel to bypass
    traverses under controlled circumstances.  For example, if you construct
    a VFS overlay on top of / which just changes how files in /usr/lib and
    /var/run are accessed, you want all the fall through cases to be optimal
    (not require any interaction with the VFS layer once prior results are
    cached by the kernel).

						-Matt