During the boot process, my Ubuntu 14.04.2 takes about 11 seconds to complete the "random: nonblocking pool is initialized" step (this is the slowest step, FYI).

  1. What does this step mean?
  2. Is it normal to take a long time to complete it?
  3. Is there any solution to this?

A sample /var/log/dmesg log from my Ubuntu 14.04.2 is shown below:

[    2.090510] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
[    2.091836] i915 0000:00:02.0: registered panic notifier
[    2.103088] ACPI: Video Device [GFX0] (multi-head: yes  rom: no  post: no)
[    2.104819] acpi device:02: registered as cooling_device4
[    2.106250] input: Video Bus as /devices/LNXSYSTM:00/device:00/PNP0A08:00/LNXVIDEO:00/input/input6
[    2.107908] [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 0
[    2.214193] psmouse serio1: synaptics: queried max coordinates: x [..5888], y [..4856]
[    2.301008] EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: (null)
[    2.334007] psmouse serio1: synaptics: Touchpad model: 1, fw: 7.4, id: 0x1e0b1, caps: 0xd04773/0xe40000/0xa0400, board id: 0, fw id: 639087
[    2.409482] input: SynPS/2 Synaptics TouchPad as /devices/platform/i8042/serio1/input/input5
[    2.914326] Switched to clocksource tsc
[    3.120191] random: nonblocking pool is initialized
[   14.745283] Adding 3986428k swap on /dev/sda5.  Priority:-1 extents:1 across:3986428k FS
[   14.875375] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[   15.027854] systemd-udevd[333]: starting version 204
[   15.316294] lp: driver loaded but no devices found
[   15.330491] ppdev: user-space parallel port driver
up vote 2 down vote accepted

I believe this particular step does not actually take a long time. The message in the dmesg log is printed when the pool has been initialized, not when initialization is started.

What Linux is doing in those 11 seconds is probably probing, identifying and initializing hardware, which does not necessarily generate entries in the dmesg log.

  • Yes, I see the same. (I hope) something harmless must be happening in the background. – Tom Sep 11 '15 at 12:46

Said, another way: No its not normal, something is taking a while to respond. Do you have any Peripheral devices you can unplug and retry booting? One of them is likely creating some problem. unplug your printer, usb memory, etc... and try rebooting. Is it faster? If it is, try inserting one device at a time back into your system, and rebooting to identify the troubling device. figure out the troubled device, and post back. you might check your disk integrity (SMART Analysis)

The log you want to look at is (probably): /var/log/syslog

you might also try going into your bios, and disabling things like the parallel port, and other unused hardware, such that you don’t need to waste time initializing ports you aren't using.

  • Unplugging all peripheral devices didn't do the trick, neither all tests you have suggested. Ubuntu still takes the same 11 seconds between those 2 steps and I cannot find out the reason. Anyway, it is not a total disaster at all. It is possible to live with. Thanks a lot for your hints. – Tom Sep 11 '15 at 12:44
  • Hey @Tom what does the command: cat /proc/sys/kernel/threads-max give you? – j0h Sep 11 '15 at 13:39
  • It shows "59582". Is it good or bad? Sorry, I am a completely newbie in regards kernel issues. – Tom Sep 11 '15 at 20:32
  • Im not sure at this point, I was delving into some other ideas about fixing your issue. I saw a couple other threads like this one on other forums, but the solutions folks had were to reinstall. Anyhow, i think "nonblocking pool" has to do with threads and thread limits. I'll post back later I gotta catch a bus home. – j0h Sep 11 '15 at 22:08

It could be trying and failing to switch video modes. Try adding nomodeset to the kernel command line and see if that helps.

In the grub bootmenu, press e to edit the current boot entry and append " nomodeset" to the line that starts with linux. Then press f10 or ctrl + x to boot the modified entry.

  • Hi @András if you could perhaps edit your answer to add instruction on how exactly one can go about adding nomodeset to the kernel? – Tshilidzi Mudau Oct 4 '16 at 8:49
  • 1
    Answer amended as requested. – András Korn Oct 5 '16 at 11:47

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Not the answer you're looking for? Browse other questions tagged or ask your own question.