Ecco cosa ho trovato nei log, non ci avevo pensato:

Dec 24 00:38:14 MyMachine squid: Avvio squid:
Dec 24 00:38:14 MyMachine squid[5420]: Squid Parent: child process 5422 started
Dec 24 00:38:15 MyMachine squid: .
Dec 24 00:38:15 MyMachine squid: ^[[65G
Dec 24 00:38:15 MyMachine squid: [^[[1;32m
Dec 24 00:38:15 MyMachine squid: OK
Dec 24 00:38:15 MyMachine squid:
Dec 24 00:38:16 MyMachine rc: Avvio squid: succeeded
Dec 24 00:38:16 MyMachine rc: Avvio kheader: succeeded