>
> On 07-Apr-99 Jay R. Ashworth wrote:
> > On Tue, Apr 06, 1999 at 11:28:46PM -0400, Cary O'Brien wrote:
> >> (from memory...)
> >>
> >> Sun OS 4.1 had a thing called a 'Translucent File System'. It somehow
> >> let you mount one file system on top of another, so you would see the
> >> underlying
> >> file system unless you changed a file, in which case the changed file would
> >> be stored in the 'top' file system. I.E. the 'top' file system would have
> >> changes. Or something like that. So if you could somehow mount a ramdisk
> >> on top of a read-only root partition...
> >
> > Your memory is correct, and this has been implemented for Linux, but I
> > don't have a pointer handy.
>
> The only reference I have managed to find to this is
>
> http://lrcwww.epfl.ch/~almesber/ifs.html
>
> The Inheriting File System. Unfortunately the last update, according to that
> reference, was made against a 0.99pl14 kernel. This whole thing sounds rather
> intriguing, and potentially _very_ useful - has anyone else heard of someone
> working on this?
>
Sadly, not me. Anyone else?
The reference to userfs reminded me of a big wide open space for
really slick Linux applications.
There ought to be a way to create things that look like file systems but
access different 'trees' of information. One example is a file system that
accesses via ftp files on other machines -- i.e. /ftp/metalab.unc.edu/pub/Linux/...
is what you would expect. Another example would be an SNMP file system. I.E.
/snmp/hostname/iso/(whatever)/sysDescr.0 returns the system descr string.
One way to implememt this is with a user-space NFS daemon and a local NFS mount.
This is how CFS (cryptographic file system) works.
A nice API (how? don't know) would make it easier to create such things.
And remember, anything can be exported with samba, so PC users can
use explorer to descend down the (virtual) file system tree.
Food for thought.
Have Fun,
-- cary
