sudo /etc/init.d/squid start
Rather than invoking init scripts through /etc/init.d, use the service(8)
utility, e.g. service squid start

Since the script you are attempting to invoke has been converted to an
Upstart job, you may also use the start(8) utility, e.g. start squid
start: Unknown job: squid
eladmin@acer1:/etc/apache2$ sudo service squid start
start: Unknown job: squid