[squid-users] squid not caching in harddisk / cpu load

Hi
i dont know why squid is not caching ( my cache_dir is alwayes free ! ),

i have 2 cache_dir and both is free ( useing about 400-500kb).

and my second problem is with squid cpu load .

i dont know why squid randomly useing 99.99% of cpu for few seconds
( 10seconds - 1min ).

normaly it useing 40% of cpu .

i have about 150 active user.

please check my squid config and recommend any things that should be
changed.

THANKS!

server :
xeon 2.8 ( without HT )
2gb ram
2*80gb sata

squid config :

*******************************************************
acl QUERY urlpath_regex cgi-bin \?
no_cache deny QUERY
no_cache deny all
cache_mem 32 MB
maximum_object_size 2048 KB
minimum_object_size 8 KB
maximum_object_size_in_memory 8 KB
ipcache_size 8192
fqdncache_size 4096
cache_dir aufs /var/spool/squid 300 32 256
cache_dir aufs /backup/squid 300 32 256
cache_access_log /dev/null
cache_store_log none
debug_options ALL,1
store_avg_object_size 50 KB
buffered_logs on

http_port 3128
httpd_accel_host virtual
httpd_accel_port 80
httpd_accel_with_proxy on
httpd_accel_uses_host_header on
*******************************************************
Received on Sat Nov 26 2005 - 13:02:16 MST