cache有问题

attiseve

我的squid+iptables透明代理，图片cache还行，mp3等大一点的文件感觉根本就没怎么cache。还是得一点一点来下载。大家有这样的问题没有？

squid.conf
=======================================================
[root@oa squid]# cat squid.conf
http_port 3128
cache_mem 800 MB
cache_swap_low 90
cache_swap_high 95
cache_dir ufs /var/cache/squid 4000 16 256
cache_access_log /var/log/squid/access.log
cache_store_log /var/log/squid/store.log
dns_nameservers 210.77.192.88

httpd_accel_host 80
httpd_accel_with_proxy on
httpd_accel_uses_host_header on

acl all src 0.0.0.0/0
acl lixiaedu100 src 192.168.100.0/24
acl lixiaedu168 src 192.168.168.0/24
acl zhaobing src 10.40.17.55/32
acl zhengyi src 60.232.94.146/32

http_access allow lixiaedu100
http_access allow lixiaedu168
http_access allow zhaobing
http_access allow zhengyi
http_access deny all

cache_effective_user squid
cache_effective_group squid
visible_hostname lixiaedu
===========================================================

iptables
===========================================================
iptables -t nat -A POSTROUTING -s 192.168.100.0/24 -o eth2 -j SNAT --to 60.232.126.154
iptables -t nat -A POSTROUTING -s 192.168.168.0/24 -o eth2 -j SNAT --to 60.232.126.154
iptables -t nat -A PREROUTING -s 192.168.100.0/24 -i eth1 -p tcp --dport 80 -j REDIRECT --to-port 3128
iptables -t nat -A PREROUTING -s 192.168.168.0/24 -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3128
===========================================================


透明代理应该是起作用了，但就是感觉效果不明显。请大家给看看。
再有：
httpd_accel_host 80
httpd_accel_with_proxy on
httpd_accel_uses_host_header on
上面这三句必须要加吗？（我试过，去掉任何一句都会有问题）我没有做反向代理。

xiao6

squid默认最大缓存对象4M
maximum_object_size 4096 KB