Linux boot speed-up removing slow/useless services

Today, after upgrade to Debian Stretch i was looking startup loaded services and system boot-up performances through systemd-analyze* command.

Looking results , excluding kernel time(4,5 sec), system took 1 minute and 42 seconds for start; OK , i don’t have an SSD, there are a lot of services like tor, virtualbox , Plasma,etc but boot time seems really too long.
This situation deserves a more detailed check, so i executed systemd-analyze blame* for understand if there is a particular slow service or if there are just so many

As you can see , outcome show that racoon.service takes 1minute and 32 secs to start.. this service (ipsec) for my needs it is useless. Therefore i typed (with sudo, or being root) Systemctl disable racoon.service

Afterthat, i restarted system and i typed again command System-analyze to see results:

Nice, we cut 1 minute and 17 seconds ; from 1 minute and 47 sec to .. 30 seconds 🙂
Probably this is a not-standard case, but with this example you can easily understand how even a single service can affect startup time.
In general,  making a check  to verify and identify which services taking time (and especially if are necessary for our needs)  it is something that ,as in this case, is really useful
*Despite my screenshots, you can execute systemd-analyze and systemd-analyze blame whitout root privileges.