Re: Link Question

[Allan Nelson <anelson jump net>]

On Wed, 09 Sep 1998, Alfonso Barreto Lopez wrote:
>Why I can't make a hard link between /opt and /usr/opt these are different
>partitions?
>What is the difference between hard and symbolic link?
>Thanks and sorry for the ignorance...

Well, you asked....:-)

Unix file systems are built around data structures called inodes.  Inodes
contain all the information about a file except the name and the data blocks
that  belong to the file.  The file names are kept in directories.

Hard links are directory entries that point to the same inode number as a file
that already exists.  This is a way to provide more than one filename or path to
a file.  Since inode numbers are only unique within a given file system they 
can't cross file system boundaries.  In your case /opt and /usr/opt are in
different file systems.

Symbolic links, on the other hand, are small files that contain the actual
path to a file.  Thus it can span file system boundaries.

Hope this helps.

___ 
Allan L. Nelson			
UNIX System Administrator
Oracle DBA