Default user after upgrade to 7.3?

I just upgraded a system from RedHat 8.0 to RedHat 9.0,
which also upgrades the version of PostgreSQL.

However, I cannot run pgsql to restore the databases
because I don't know a 'default' user with permission
to run pgsql:

postmaster successfully started
LOG:  database system was shut down at 2003-11-06 10:27:18 MST
LOG:  checkpoint record is at 0/80193C
LOG:  redo record is at 0/80193C; undo record is at 0/0; shutdown TRUE
LOG:  next transaction id: 480; next oid: 16976
LOG:  database system is ready
FATAL:  IDENT authentication failed for user "root"
FATAL:  IDENT authentication failed for user "postgres"
FATAL:  IDENT authentication failed for user "swampler"

Am I missing something obvious?  I couldn't find any
mention of needing to add a default user (I thought user
postgres was the default...) in the installation docs.
(And how do I do so, given that I can't run createuser
as anyone...?)

Thanks!
-Steev
--
Steve Wampler -- swampler@noao.edu
Quantum materiae materietur marmota monax si marmota
                    monax materiam possit materiari?