Forum OpenACS Q&A: ConnectDBStart() -- connect failed: not such file or directory

The following error prevents me from connecting to the postgresql database.

psql: connectDBStart() -- connect() failed: No such file or directory
Is the postmaster running locally and accepting connections on Unix
socket '/tmp/.s.PGSQL.5432'?

The Postmaster indeed runs and stays up, but it just won't accept connections on port 5432. I ran nmap to see what ports are alive and port 5432 doesn't show up.
My ACS/AOLServer/psql combo had been running smoothly for many months until this problem occured. I don't see any stale lock files on /tmp. Yesterday I ran into a problem with db2 (the berkeley db): btree version 6 is not compatible with a version of db2 I currently have. I would assume this problem has nothing to do with psql not allowing connections, would it? Also, earlier this morning, I had to reboot my computer after 166 days of non-stop operation... I had lots of empty kdeinit's that had been spawned in the last few hours. I could never determine what caused these to spawn so prolifically, since my computer froze and I had to cold-reboot it. I mention this seemingly irrelevant fact because it was after this reboot that my psql stopped working. I also had problems with a font not being found which was preventing me from running the program startx to start my xserver. I worked around it by starting xfs (the font server) manually before calling startx.
I hope that by my mentioning as much as possible about the context in which the problem is occurring, someone might point me to the right next step to take.
In the meantime I'll see if I can run the postgres server in any manual, debug mode, or see if I can find a log file (haven't so far) with relevant messages.
Gustavo-

I took the easy road out. Lazy me, huh? I uninstalled my non-functional postgresql by doing a:

    rpm --erase --force --verbose postgres<*whatever*>  
    (I had a total of 6 postgres* modules...)
    

I started with a clean slate, and re-installed every postgres* module I had uninstalled in the right sequence so as to fulfill every module's dependency needs.
I then modified /etc/rc.d/init.d/postgresql and changed every PGDATA assignement to /home2/psql/mydbdatadir/... This worked fine. I could start the postmaster as root via /etc/rc.d/init.d/postgresql. My old database is still here, intact, and I find myself liking postgresql more and more each day. Sad thing of this chicken approach is, I won't know what happened. In the process of 'solving' this problem I learned about the importance of doing backup dumps in case something goes awry... pg_dumpall seems to be a pretty handy command which I'll put to use today.