My company has 4 Dell R710's all running RHEL 5.5 and Oracle 11gR2. In the last 2 weeks we have had 2 of the servers hang with NO indication from RH or Oracle that their was any kind of kernel panic or errors from Oracle. The server just stops responding and when I check the IDRAC console it's just a black screen and doesn't respond to keystrokes. There are no hardware alerts on the IDRAC either. This has also happened several more times in the last 18 months and there's no pattern or commonality to the time we see the servers hang.
We are forced to reboot the server when this happens and it comes back up ok, but there's nothing in /var/log/messages at the time it became unresponsive. Oracle alert logs don't show anything either that would explain why the server became unresponsive.
Has anyone else ever experience this kind of behavior? Especially while running the same hardware, OS, and database versions.