Comment 3 for bug 1159464

Perhaps I did not understand the full intent of the comment in the
original code, "FIXME: add a custom mounts configurable system".

It might be that what the author of that comment had in mind was
not just full configurability of the names and locations of the root
and user persistent filesystem images, but generalizing the code
to allow arbitrary filesystem mount points, and the possibility of
more than two of them.

For example, we could introduce a new boot option for persistent
filesystems:

    persist=<fs-mount>:<fs-image>[, ...]

This would allow any number of persistent overlay filesystems, and
their mount points, to be specified. The current situation, with one
root and one user overlay filesystem, would be just one possible
case, specified like this:

    persist=/:/casper-rw,/home:/home-rw

It appears that given the existing infrastructure for overlay filesystems,
this would be fairly easy to write, consisting of not much more than
the code to interpret and apply the boot option proposed above.

One obvious use for this functionality would be to have the persistent
data for different users contained in separate filesystems, to make it
possible to move them around independently of each other.

Is there any interest in pursuing this feature? If so, I would volunteer
to write code for it, although I would also want to consult with other
people who were familiar with the issues involved.

-- Ian Bruce