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ubuntu:boot:speed_up_boot [2019/11/25 22:06] – peterubuntu:boot:speed_up_boot [2020/07/15 09:30] (current) – external edit 127.0.0.1
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 ====== Ubuntu - Boot - Speed up boot ====== ====== Ubuntu - Boot - Speed up boot ======
 +
 +===== Check startup time =====
 +
 +Check how long it takes to boot:
 +
 +<code bash>
 +systemd-analyze time
 +</code>
 +
 +returns:
 +
 +<code bash>
 +Startup finished in 16.619s (firmware) + 10.201s (loader) + 36.729s (kernel) + 41.034s (userspace) = 1min 44.586s
 +graphical.target reached after 23.396s in userspace
 +</code>
 +
 +This shows how long it takes for the Linux kernel and base system services to load.  
 +
 +It shows you how much time is required, from the moment the kernel is loaded until you are dropped to the Linux console.
 +
 +It doesn’t account for the time your graphical interface requires to boot up. 
 +
 +----
 +
 +===== Check startup time for the graphical interface to initialize =====
 +
 +You can also see the time required by the graphical interface to initialize with this command:  
 +
 +<code bash>
 +systemd-analyze critical-chain graphical.target
 +</code>
 +
 +returns
 +
 +<code bash>
 +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 @23.396s
 +└─multi-user.target @23.396s
 +  └─libvirt-guests.service @23.378s +18ms
 +    └─libvirtd.service @3.189s +20.187s
 +      └─network.target @3.189s
 +        └─NetworkManager.service @2.333s +855ms
 +          └─dbus.service @2.223s
 +            └─basic.target @2.207s
 +              └─sockets.target @2.207s
 +                └─docker.socket @2.206s +965us
 +                  └─sysinit.target @2.203s
 +                    └─apparmor.service @1.458s +745ms
 +                      └─local-fs.target @1.457s
 +                        └─run-user-1000-gvfs.mount @15.641s
 +                          └─run-user-1000.mount @14.700s
 +                            └─swap.target @1.607s
 +                              └─dev-mapper-ubuntu\x2d\x2dvg\x2dswap_1.swap @1.565s +36ms
 +                                └─dev-mapper-ubuntu\x2d\x2dvg\x2dswap_1.device @1.565s
 +</code>
 +
 +
 +This shows that the graphical user interface loaded in 23.396 seconds.  
 +
 +<WRAP info>
 +This doesn’t account for the time required to load desktop utilities.  
 +
 +To enable/disable those, launch your desktop environment startup manager.
 +</WRAP>
 +
 +----
 +
 +===== Check which services takes most time =====
 +
 +
 +Use the following command to check which service takes most of time
 +
 +<code bash>
 +systemd-analyze blame
 +</code>
 +
 +returns
 +
 +<code bash>
 +         30.898s apt-daily.service
 +         20.417s rsyslog.service
 +         20.187s libvirtd.service
 +          5.774s systemd-networkd-wait-online.service
 +          3.654s docker.service
 +          1.841s apt-daily-upgrade.service
 +          1.820s snapd.service
 +          1.487s plymouth-quit-wait.service
 +           993ms dev-mapper-ubuntu\x2d\x2dvg\x2droot.device
 +           855ms NetworkManager.service
 +           768ms fwupd.service
 +           752ms udisks2.service
 +           745ms apparmor.service
 +           736ms networkd-dispatcher.service
 +           725ms snap-gnome\x2dcalculator-544.mount
 +           710ms networking.service
 +           697ms thermald.service
 +           680ms snap-netbeans-10.mount
 +           674ms snap-gnome\x2dlogs-81.mount
 +           661ms systemd-resolved.service
 +           643ms systemd-timesyncd.service
 +           642ms systemd-logind.service
 +           558ms ModemManager.service
 +           550ms apport.service
 +           544ms gpu-manager.service
 +           528ms motd-news.service
 +           502ms grub-common.service
 +...
 +</code>
 +
 +
 +<WRAP info>
 +You can navigate the list with your arrow keys or **PAGE UP** and **PAGE DOWN**. 
 +
 +Press **q** to quit.
 +</WRAP>
 +
 +
 +
 +----
 +
 +===== Check the critical chain =====
 +
 +Analyze each major process to determine how long it takes to run.
 +
 +For example, to get further information on the AppArmor Service, to see if you can disable it or speed it up, use:
 +
 +<code bash>
 +systemctl status apparmor.service
 +</code>
 +
 +returns:
 +
 +<code>
 +● apparmor.service - AppArmor initialization
 +   Loaded: loaded (/lib/systemd/system/apparmor.service; enabled; vendor preset: enabled)
 +   Active: active (exited) since Sat 2019-11-23 10:23:26 GMT; 2 days ago
 +     Docs: man:apparmor(7)
 +           http://wiki.apparmor.net/
 +  Process: 1181 ExecStart=/etc/init.d/apparmor start (code=exited, status=0/SUCCESS)
 + Main PID: 1181 (code=exited, status=0/SUCCESS)
 +
 +Warning: Journal has been rotated since unit was started. Log output is incomplete or unavailable.
 +</code>
 +
 +Also check the journal:
 +
 +<code bash>
 +journalctl -u apparmor.service
 +</code>
 +
 +returns:
 +
 +<code>
 +-- Logs begin at Sun 2019-11-24 02:17:01 GMT, end at Mon 2019-11-25 21:05:42 GMT. --
 +-- No entries --
 +</code>
 +
 +
 +
 +----
 +
 +===== Disabling auto-start of services during boot =====
 +
 +If you want to disable auto-starting of services during boot you can use the following command:
 +
 +<code bash>
 +sudo systemctl disable some-time-eater-service.service --now
 +</code>
 +
 +However, you might want to see which other services needs the service in question. To check use the following command
 +
 +<code bash>
 +systemctl list-dependencies some-service.service --reverse
 +</code>
 +
 +Note: Replace **some-service.service** with actual service name.
 +
 +<WRAP important>
 +
 +**WARNING:**  Disabling a service doesn't make a service non-startable.  If you reboot, you could notice the service (daemon) is still running.  That’s because other dependencies may launch it, even if it’s disabled. 
 +
 +Try to see what those may be:
 +
 +<code bash>
 +systemd-analyze blame | grep some-service
 +</code>
 +
 +If you want to completely disable it, read the next section.
 +
 +</WRAP>
 +
 +
 +----
 +
 +===== Disabling services completely =====
 +
 +If you want to completely disable a service so that it can't be started, you should use mask instead of disable. Like this
 +
 +<code bash>
 +sudo systemctl mask <SERVICE-NAME>
 +</code>
 +
 +Replace the <SERVICE-NAME> with actual name of a service.
 +
 +The difference between mask and disable is mask make a service completely disable, you can't start it.  You must unmask to start it with systemd (you can still start with service).  But disable simply disables auto-start of a service, you can start it later.
 +
 +For example, after masking the some-service service, if you tried start it with systemctl the following message is shown
 +
 +Failed to start some-service.service: Unit some-service.service is masked.
 +
 +----
 +
 +===== Re-enable a service =====
 +
 +If you want to re-enable a service:
 +
 +<code bash>
 +sudo systemctl unmask <SERVICE-NAME>
 +sudo systemctl enable <SERVICE-NAME>
 +</code>
 +
  
ubuntu/boot/speed_up_boot.1574719569.txt.gz · Last modified: 2020/07/15 09:30 (external edit)
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