Help! System catalogs vanished!

Hi there,

I'm having a just wonderful Friday at work. Not.

At around 2am this morning, probably in the middle of the nightly
scheduled VACUUM ANALYZE, the UPS on my server failed.

This morning, I have no databases.

The details:
PostgreSQL 7.0.3 on IRIX 6.5.11m.

When I started the machine this morning, I couldn't start the postmaster
with pg_ctl at all. Firstly it claimed there was another postmaster
running (there wasn't) and then when I removed the postmaster.pid file,
pg_ctl just said it couldn't execute postmaster.

When I started postmaster by hand with:

/usr/freeware/bin/postmaster -D /usr/data/pgsql -o "-i -S"

it started BUT now watch this:

jove bin$ psql stowe3
Welcome to psql, the PostgreSQL interactive terminal.

Type: \copyright for distribution terms
\h for help with SQL commands
\? for help on internal slash commands
\g or terminate with semicolon to execute query
\q to quit

stowe3=> \d
stowe3=> \dS
stowe3=> select now();
stowe3=> select version();
stowe3=>

This is, to my mind, extremely unhealthy. To my customers' minds too for
that matter.

The behaviour is the same no matter which of the 8 databases I connect
to. Also, I don't know if it's relevant, but all of them have pg_table
files of zero length.

SO, I really need to sort this out pronto-urgently.
If I can't do anything to restore them within the next few hours, I'll
have to do a fresh initdb and start restoring and reconstructing.

Frankly though, I'd much rather have a weekend.

*sigh*

Hal