Kubuntu boot time: 16.04 -18.04

[Ralf Mardorf]

On Mon, 16 Jul 2018 11:11:57 +0200, Peter McD wrote:
>I have on an SSD three OS with KDE and the boot time differs between 
>them. All are updated.
>
>Each from the boot selection menu to the login mask
>
>Kubuntu 18.04       50s
>Kubuntu 16.04.4     21s
>opensuse Tumbleweed 16s
>
>Significant is the boot difference between the two Kubuntus.
>
>I would like to check the different log files, which should I look for?

Hi,

a startup could slow down, if a partition is checked, so the first
way to go, would be to disable a splash screen and taking a look at
the startup messages during startup.

That all Linux installs are using the same init system and the same
desktop environment is completely unrelated to the amount of services
that get started or individual system configurations.

[rocketmouse at archlinux ~]$ systemd-analyze
Startup finished in 1.758s (kernel) + 18.758s (userspace) = 20.516s
graphical.target reached after 18.601s in userspace
[rocketmouse at archlinux ~]$ systemd-analyze critical-chain
The time after the unit is active or started is printed after the "@" character.
The time the unit takes to start is printed after the "+" character.

graphical.target @18.601s
└─multi-user.target @18.601s
  └─alice-dhcp.service @2.450s +16.150s
    └─basic.target @2.439s
      └─sockets.target @2.438s
        └─dbus.socket @2.438s
          └─sysinit.target @2.435s
            └─systemd-update-done.service @2.425s +9ms
              └─ldconfig.service @2.002s +421ms
                └─local-fs.target @1.999s
                  └─run-user-1000.mount @10.967s
                    └─swap.target @1.917s
                      └─dev-sda10.swap @1.656s +18ms
                        └─dev-sda10.device @1.573s
[rocketmouse at archlinux ~]$ systemctl list-units --type service | grep loaded\ units
39 loaded units listed. Pass --all to see loaded but inactive units, too.
[rocketmouse at archlinux ~]$ systemctl list-units --type service --all | grep loaded\ units
70 loaded units listed.

https://wiki.archlinux.org/index.php/Improving_performance/Boot_process#Analyzing_the_boot_process
https://packages.ubuntu.com/bionic/systemd-bootchart

Regards,
Ralf