SQUID设置问题

赫连小妖

我在webmin中配置squid，有个提示：
Your Squid cache directory /var/spool/squid has not been initialized.This must be done before Squid can be run
之后我点initialize，出现一个错误提示：
Initializing the Squid cache with the command squid -f /etc/squid/squid.conf -z ..


FATAL: Could not determine fully qualified hostname.  Please set 'visible_hostname'

Squid Cache (Version 2.5.STABLE3): Terminated abnormally.
CPU Usage: 0.010 seconds = 0.010 user + 0.000 sys
Maximum Resident Size: 0 KB
Page faults with physical i/o: 400
我是搞不懂，求高手指点一下。
期待中。