Backend died abnormally - postgresql 7.2.1-5

Hello all,

I am happy to report that this is the first time I have had a moment of
trouble with postgresql.

I have upgraded to 7.2.1-5 from version 7.1.3-2. (Redhat rpms)


I did a pg_dumpall on the old version, installed the new version and
then restored the databases.

The problem seems to be that the backend is dieing. This gives this
error in apache logs.

    ###############################################################
    NOTICE:  Message from PostgreSQL backend:
        The Postmaster has informed me that some other backend
        died abnormally and possibly corrupted shared memory.
        I have rolled back the current transaction and am
        going to terminate your database system connection and exit.
        Please reconnect to the database system and repeat your query.
    DBD::Pg::db disconnect failed: rollback failed at
/usr/local/lib/perl5/site_perl/5.6.1//FS/UID.pm line 68.
    NOTICE:  Message from PostgreSQL backend:
        The Postmaster has informed me that some other backend
        died abnormally and possibly corrupted shared memory.
        I have rolled back the current transaction and am
        going to terminate your database system connection and exit.
        Please reconnect to the database system and repeat your query.
    DBD::Pg::db commit failed: begin failed at
/usr/local/lib/perl5/site_perl/5.6.1//FS/Record.pm line 270.

#################################################################


I have search the archives/docs and see some talk on a lack of memory
and/or swap space might be the cause. I see no indication of this with
the 'free' command take right after errors accorded.


################################################################
  [root@nemisis httpd]# free
            total       used       free     shared    buffers     cached
Mem:        512440     504104       8336       1240     130028
303896
-/+ buffers/cache:      70180     442260
Swap:        80284        312      79972

################################################################

1. Does this system need more memory?

2. What should be my next step in finding this problem?

Thank you for your time,
Rick Eicher II