On Sun, 17 Oct 1999, David Summers wrote:
> What is wrapfs and mfs? Sound interesting. Could you provide pointers to
wrapfs (or fist) is a project which implements stackable filesystems in
the kernel. Basically, you can define a new filesystem which is based on
ext2 but adds features to it (e.g. ACLs, migration, encryption, etc), at
a very marginal cost (the author says 7%). However, unlike userfs, the
filesystem code runs _as a kernel filesystem_, and thus it's not a very
good idea to prototype code that way. userfs is superior in that aspect.
However, I already have prototyped my code, and I have found problems with
userfs that I can't easily solve.
fist is available at:
ftp://shekel.mcl.cs.columbia.edu/pub/fist
A paper describing it is included in the fist-common archive.
The distributed archive has a single compilation error which is easy to
correct and may be fixed in -current since I reported it some time ago.
mfs is the name for a filesystem based on wrapfs which implements
transparent data migration/unmigration (HSM-like on a file based level).
The only part of mfs which is at this time available is the tapefs
filesystem, a read only tape filesystem with indexing, which is
implemented on top of userfs.
My patches for userfs and tapefs are available at:
http://www-internal.alphanet.ch/archives/local/alphanet/linux/drivers/userfs/2.2.x-libc6/
(A non Microsoft browser is required).
> get it to work under Linux Kernel 2.2.X. I grabbed your 0.9.7-pre1 dist
> and it stops compiling at:
It's not mine :)
I have this which was written by someone else:
userfs-0.9.5pre.tar.gz
and then my patch so that it mostly really works
userfs-0.9.5pre-to-SuSE-6.0-patch.gz
It's available in the above directory. However, as I have already stated,
it looks like userfs doesn't really work if you have multiple processes
accessing a filesystem. Maybe it's by design (?), or it's because of the
2.2.x patches which broken something.
> and I was wondering what was different between our two environments that
> it would compile for you and not for me? I'm using RedHat 6.1 with
> Linux Kernel 2.2.12.
It's always possible. Try the patches, however.
> glibc-2.1.2
yes, I run 2.0.x
> egcs-1.1.2
using gcc-2.7.2.3
> If you are still working on things then sorry to bother you....
I am not the userfs author, and there are other people who seem to
still work on it.
