RHEL5 performance

[Nicosia Gaetano]

  Hi to All,

this is my "scenario".

1) I have a Server Poweredge Dell T100 with RHEL5 installed;
2) This Server is new and the hardware has been tested;
3) On this Server I have installed Oracle DB 11g R2;

I am connected to Server through Client in a little home Intranet, and 
all work without problems.

But I realize that, in a short time, the server response time grow 
greatly, and there is a remarkably deterrioration of performance and I-O.

Often, I must restart the server.

Someone has an idea o suggestion for me ?

Best Regards
Gaetano