ORA-03113: end-of-file on communication channel - Due to alert log reaching maximum file size.

# Problem - pmon process crashed - nothing in the alert log - startup nomount fails with ORA-03113

[oracle@dev-oranode-6 bdump]$ sqlplus '/ as sysdba'

SQL*Plus: Release 9.2.0.4.0 - Production on Mon Jun 15 10:12:20 2009

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

Connected.
SQL> startup nomount;
ORA-03113: end-of-file on communication channel

# Cause :- Alert log had reached 2GB maximum file size.
# Solution :- Rename the alert log, and try again.