bash fork: Resource temporarily unavailable

[rkmr.em at gmail.com]

i am using nginx version 0.6.31, to server static files config files below.

now regularly when I login and I try to do something I get this error,
and I am not able to start anything.. i have over 10GB of free RAM..
how to fix this problem?



bash fork: Resource temporarily unavailable


my requests are like this
Active connections: 30
server accepts handled requests
1869887 1869887 1864882
Reading: 0 Writing: 30 Waiting: 0

I get this message on /var/log/messages
May 19 17:05:05 XXX kernel: possible SYN flooding on port 80. Sending cookies.

uname -a
Linux XXX 2.6.25.3-18.fc9.x86_64 #1 SMP Tue May 13 04:54:47 EDT 2008
x86_64 x86_64 x86_64 GNU/Linux


free -m
             total       used       free     shared    buffers     cached
Mem:         16086       8757       7328          0        164       5278
-/+ buffers/cache:       3314      12771
Swap:         1983          0       1983



nginx - conf

user  mark;
worker_processes  4;

error_log  logs/error_staticfarm.log;
pid        logs/nginx_staticfarm.pid;


events {
    worker_connections  1024;
}

http {
    include       mime.types;
    default_type  application/octet-stream;
   client_header_buffer_size	8k;
    large_client_header_buffers  4  8k;
    fastcgi_buffers      32 4k;
    fastcgi_buffer_size  4k;
    sendfile        on;
    #tcp_nopush     on;

    keepalive_timeout  0;
    #keepalive_timeout  10;

    gzip  on;

    server {
        listen       80;
        server_name  localhost;
        location /nginx_status {
            stub_status on;
            access_log   off;
        }
        location /static{
            root   /home/mark/staticfarm/;
            access_log   off;
        }
    }
}