After reboot, squid -k can not send stop signal again

If reboot and squid -k says it can not send stop signal again, means that squid.pid is missing
Check squid.pid in the system and if missing, here is what i can suggest :
Look into a previous post in this website, then shutdown squid
squid -k shutdown

Create squid.pid (usually squid.pid located in the same directory with log files)
touch squid.pid

squid.pid chmod permission
-rw-r--r--

squid.pid chown permission
root : squid

Since it’s empty, we must make Squid to rewrite a squid.pid file
Create Squid swap directories
squid -z

Run Squid
squid

then try reboot