Subject: Re: path component substitutions (was diskless booting)
To: Stefan Grefen <>
From: Ty Sarna <>
List: tech-kern
Date: 03/15/1994 14:54:46
Stefan Grefen wrote:
> Sorry, than I got something wrong in a previous post, I assumed that it was
> not working through symlinks. These kind of conditional symlinks is 
> useful, but than I don't understand why it doesn't work with NFS.

It does work through symlinks, and that's how it's normally used.
You can also cat /foo/@sys/file if you want.

The reason it doesn't work with NFS is because it hasn't been
implemented in NFS. The reason it hasn't been implemented in NFS is that
the NFS code is truly gross and will make correct implementation a
little tricky.

> But you can use it to have source on a readonly medium  (CDROM, ro mounted
> filesystem) and do a compile with out  building a symlink tree first.

Yes, as I said it's useful. I don't see why the two are mutually

> I know, (masscomp springs to mind here ...) but it was sometimes a nightmare
> educating the users why they couldn't find there file right now ...

I'm not sure what you mean. Why couldn't they find a file?

It's not difficult to educate users about this at all. Remember where
AFS comes from, a univerity environment with users of widely varying
proficiencies. I've never seen anyone have trouble figuring it out...
even the same people who can't grasp that "mail *" doesn't mail to
everyone on the system :-)

> > Great! TFS is useful for many things, I just don't think this is one of
> > them (particularly the original case that restarted this discussion --
> > TFS wouldn't work there).
> Of course it would. You just use a different obj. filesystem for each 
> architecture.

Rememeber the original case that started this discussion -- diskless
swap files.  One swap file per architecture isn't going to work well :-)

Ty Sarna                 "As you know, Joel, children have always looked        up to cowboys as role models. And vice versa."