low open file

[Thomasps]

Hi
I got a 3 node cluster implemented with OS Linux and 10g RAC

uname -a
Linux XXXX 2.6.9-34.ELsmp #1 SMP Fri Feb 24 16:56:28 EST 2006 x86_64 x86_64 x86_64 GNU/Linux
[root@xxxx etc]# sysctl -a | grep fs.file-max
fs.file-max = 1599224

I know fs.file-max is not set to oracle recoomended value (fs.file-max = 65536) rather it is still the default value.

Now, when I start oracle i get the message in alert log as

WARNING:Oracle instance running on a system with low open file descriptor limit. Tune your system to increase this limit to avoid
severe performance degradation.

[oracle@xxxx ~]$ ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
file size               (blocks, -f) unlimited
pending signals                 (-i) 1024
max locked memory       (kbytes, -l) 50000000
max memory size         (kbytes, -m) unlimited
 open files                      (-n) 131072 
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
stack size              (kbytes, -s) 10240
cpu time               (seconds, -t) unlimited
max user processes              (-u) 131072
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

So, can anybody tell me from where the warning originates? And what is the solution?