Symbolic links and RFS

[Eduardo Krell]

In article <31533 at bu-cs.BU.EDU> bzs at bu-cs.BU.EDU (Barry Shein) writes:

>Symlinks generalized hard links by delaying the evaluation of the file
>path until access time (although the effect seems more dramatic this
>is basically what the difference is.)

Well, it looks to me that the big difference is that symbolic links
allow you to go outside your file system. You just can't do that with
hard links.

In an NFS/RFS environment, either way of interpreting symbolic links
(by the client or the server) will break something. We need something
more powerful. Apollo extended the symbolic links to include an
environment variable in the link text. Then you can have symbolic
links which look like "/$(HOST)/foo/bar" which will expand to whatever
you $HOST variable is set.

Locus had a way of making a symbolic link to point to the local
root (ie, relative to the server) by having a special name like
"/<LOCAL>" being interpreted by the kernel to refer to the local
root and not the client's root. There wasn't an actual "<LOCAL>"
entry in /, it's just a special name which the kernel knows about.
    
Eduardo Krell                   AT&T Bell Laboratories, Murray Hill, NJ

UUCP: {att,decvax,ucbvax}!ulysses!ekrell  Internet: ekrell at ulysses.att.com