After uprading to Ubuntu 16.04 LTS I noticed that it boots noticeably slower, compare with 14.04. Is it possible solve this issue without extensive reconfiguration of various services and system settings? 14.04 boots much faster, without the necessity to apply additional changes. Below is systemd-analyze blame output.

         24.731s apt-daily.service
         15.651s grub-common.service
         15.387s networking.service
         15.273s ondemand.service
         11.437s dev-sda3.device
         11.226s irqbalance.service
         11.015s apport.service
          9.972s NetworkManager.service
          9.001s accounts-daemon.service
          8.886s apparmor.service
          8.698s ModemManager.service
          7.709s lightdm.service
          7.216s thermald.service
          6.287s NetworkManager-wait-online.service
          5.351s polkitd.service
          5.047s systemd-tmpfiles-setup.service
          4.308s systemd-user-sessions.service
          3.851s console-setup.service
          3.491s gpu-manager.service
          2.704s rsyslog.service
          2.187s systemd-backlight@backlight:intel_backlight.service
          2.067s plymouth-start.service
          1.931s bluetooth.service
          1.905s systemd-udevd.service
          1.398s avahi-daemon.service
          1.370s systemd-tmpfiles-setup-dev.service
          1.143s systemd-modules-load.service
          1.040s resolvconf.service
          1.013s dev-disk-by\x2duuid-b6b1a8eb\x2d15a0\x2d4f95\x2da7d4\x2df5291de0b7a8.swap
           851ms systemd-journald.service
           734ms udisks2.service
           651ms upower.service
           644ms iio-sensor-proxy.service
           625ms alsa-restore.service
           619ms systemd-logind.service
           615ms keyboard-setup.service
           536ms colord.service
           495ms dns-clean.service

Here is /var/log/boot.log output.

  • Dist upgrade never worked well – Bruno9779 Mar 2 '17 at 14:34
  • You have a hard drive (not SSD), and systemd doesn't (anymore) include a "readahead" solution whereas Ubuntu 14.04 might have included one? I think ureadahead (google suggests it might not be compatible with systemd). – sourcejedi Mar 2 '17 at 17:03
  • Where is specified ureadahead service? – sonex Mar 2 '17 at 17:27
  • In the ureadahead package... which depends on upstart (it only seems to provides an upstart service, nothing for any other init system). – sourcejedi Mar 19 '17 at 13:49

I've actually been wondering about how Ubuntu handled this. Now you come to ask, it looks like they didn't.

From the timings, I assume you have a hard drive, as opposed to a nice fast SSD.

We can also see you're using systemd. Some versions of systemd included a "readahead" solution, but not any more. It doesn't look like you have it (looking at the blame list).

Minimizing boot on a hard drive requires some careful pre-reading of files. Something like reading entire files at a time, to avoiding interleaving reads of different files... The point is to minimize the number of slow mechanical drive-head movements. Implementing readhead significantly improved Ubuntu's boot times on traditional hard drives.

Ubuntu 14.04 used upstart by default, right? When Ubuntu switched from upstart to systemd, they effectively abandoned their "ureadahead" service, with the idea to use systemd-readahead.

systemd-readahead was then abandoned due to lack of developer interest (i.e. admitting they all have nice fast SSDs :).

| improve this answer | |
  • So, what I can do to make it boot up faster? – sonex Apr 13 '17 at 12:57
  • @sonex upgrade to an SSD, or provide development/qa resources to revive systemd-readahead. TBH I'm not sure how much could actually have broken... the point where it needs to be hooked in to the boot process might have changed slightly. – sourcejedi Apr 13 '17 at 14:17
  • It's new computer, no need to upgrade hardware or anything. – sonex Apr 13 '17 at 14:22
  • There is. If you want it to boot fast and you originally chose to buy a slow Hard Disk Drive and not a Solid State Drive. Unless you can get one of the readahead services running. If you manage to do that, please provide an answer to this question :). – sourcejedi Apr 13 '17 at 18:41
  • I updated systemd-analyze blame output to current. Also, I have mentioned readahead installed, seems its not used? – sonex Apr 13 '17 at 21:14

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