I’ve recently upgraded my machine from Ubuntu 14.04.4 to Ubuntu 16.04.1, but while my computer used to boot in about 40 seconds, after the upgrade boot times increased considerably to 2 to 3 minutes.
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[ 9.776990] usb 3-4.4.2: pl2303 converter now attached to ttyUSB0 [ 11.510201] floppy0: no floppy controllers found [ 98.444400] vboxdrv: Found 8 processor cores [ 98.460319] vboxdrv: TSC mode is Invariant, tentative frequency 4026996449 Hz [ 98.460321] vboxdrv: Successfully loaded version 5.0.26 (interface 0x00240000 |
There’s a bit 87 seconds gap between checking for the floppy, and VirtualBox drivers loading. So there’s definitely an issue here, but the log does not exactly give a clear queue.
I’ve read you could use systemd-analyze to find which process(es) may be slowing down your computer at boot time:
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systemd-analyze blame 8.121s apt-daily.service 7.658s NetworkManager-wait-online.service 931ms docker.service 710ms winbind.service 695ms nmbd.service 647ms samba-ad-dc.service 543ms ModemManager.service |
Two processes are taking close to 8 seconds, but those 16 seconds still do not explain why it takes 2 minutes more to boot…Eventually, I realized systemd-analyze has a few more tricks up its sleeves:
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systemd-analyze Startup finished in 5.784s (kernel) + 3min 651ms (userspace) = 3min 6.425s systemd-analyze plot > test.svg |
The first command shows there’s no problem with the kernel itself, and something is slow in user space. The second command draws a huge boot chart (SVG), whose shape looks like the picture below.
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systemd-analyze Startup finished in 5.764s (kernel) + 11.282s (userspace) = 17.047s systemd-analyze plot > test2.svg |
On a rather unrelated note, yesterday I also decided to look into Firefox performance issues (switching or closing tabs would take 2 to 3 seconds), and I discovered recent versions of Firefox browser (47+ and greater) include support for “about:performance” tab showing which add-on(s), plugin(s), or page(s) may be problematic. Just let it run for a while, and go about your business browsing the web, and then come back to the tab to check if any has many alerts. It helped me find an add-on slowing down browsing considerably, so I disabled it, and performance is now much better.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
It’s probably some stupid network daemon trying to search for a modem on each serial port, or something.
I can’t find the “Prolific Technology Serial Controller” in the pink diagram. Can you put an arrow in it … ?
@anon
That’s very weird. This morning 3+ minutes boot time again without USB to TTL board.
The new chart makes it look like it’s because of my USB WiFi dongle…
@Sander
It’s Line 11 starting with dev-serial-by/x2did-usb/…
But as per my comment above, it might not be the root cause.
That’s nice troubleshooting. Thanks for the tip on Firefox as well.
Cheers.
I Like This Post.
So this morning without debug board nor wifi dongle it booted in 17 seconds. I’ll keep updating this comment with boot times:
11/08 – 17 seconds
12/08 – 17 seconds
13/08 – 3 minutes 6 seconds
I can see some new messages in dmesg that I did not notice when I first wrote the article:
My external USB hard drive seems to have troubles…
@cnxsoft
I get those same error messages on all my USB drives and on two different computers. Ubuntu 16.04 / 4.4.0-36. Seems to be a kernel problem, not a problem with the HDDs:
https://bugzilla.redhat.com/show_bug.cgi?id=1351305
@Grumbel
I saw that post too, but I haven’t seen it discussed by other on Ubuntu forums. I had not really investigated, as actually my HDD does seem to work just fine, so you must be right.