Squid:
service squid stop
rm -rf /var/log/squid/*
rm -rf /var/spool/squid/*
squid -z
service squid start
Squid3:
service squid3 stop
rm -rf /var/log/squid3/*
rm -rf /var/spool/squid3/*
squid3 -z
service squid3 start
Fonte: vivaolinux.com.br usuário wellingtonpg