Currently we are in the process of setting up Oracle Identity Management at the University. 3 databases are being configured for development, testing/qa, and of course production. Our other 15+ instances are running RHEL4 64bit with Oracle 10.2.0.4, so this will be the first RHEL5 64bit install we've done for Oracle.

Everything went according to plan until applying the 11.1.0.7 patch-set. After which the database didn't start and produces the following output:

ORA-27103: internal error.
Linux-x86_64 Error: 11: Resource temporarily unavailable.
Additional information: -1.
Additional information: 1.

Well it turns out that its a known bug with 11.1.0.7 installs on 64bit Linux where the SGA is greater the 3Gb. After downloading p7272646_11107_Linux-x86-64.zip and installing it with Opatch everything is back to functioning like normal.