Symbolic user names and RFS

[Jim Rees]

In the apollo domain file system, users are identified by unique ID (user UID,
not to be confused with unix user ID).  The UID is a 64 bit number guaranteed
unique across all apollo nodes everywhere.  Since no two users ever have the
same UID, there is never any conflict, even when you take two networks that
were previously disjoint, and conjoin them.

Unfortunately, most unix programs want 32 bit user IDs, so we have to have a
mapping.  But this only affects what you see when you do 'ls -l', it has no
affect on access rights checking.  What gets sent over the net is the 64
bit unique ID.