adding profile to boot line

[vsreeser]

What is the effect of adding profile to this line in grub?

linux    /boot/vmlinuz-3.19.0-30-generic root=UUID=61f2db04-60e6-43fb-bd9d-c7adbc711d1a ro  quiet splash profile

i read somewhere that it would decrease boot time, although details were sketchy. Is there any real benefit to using this or should I just discard it?

[Qqmike]

Sorry to be pedantic, but did you try it?

[vsreeser]

Sorry to be pedantic, but did you try it?

I did. Didn't seem to make much difference.

[Qqmike]

(I have not tried this, btw.)

This is a proven technique that can help the boot process. It has actually been around since Ubuntu 6.04, so it has been tested and tested and does work

So add it in
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash profile"
sudo update-grub
re-boot

During this next boot time you will see a noticeable SLOW DOWN. This is normal because Grub is now running the profile. This is quite necessary.

Once the boot up is complete, open up that /etc/default/grub file, remove the profile entry you just added, and re-run the command sudo update-grub2. Now reboot your machine again and see if you don't notice a distinct speed increase in your boot times.

Instead of sudo update-grub2, I think just sudo update-grub.
http://www.ghacks.net/2010/07/12/spe...nes-boot-time/
http://www.ubuntubuzz.com/2012/01/how-to-increasespeed-up-ubuntu-booting.html

[claydoh]

Old how-to for old linuxes clogging the search engines. The grub option you added only worked with the old (and iirc optional) readahead daemon, no longer in use. We use ureadahead, which is installed by default - you may notice mention of it when running apt in the command line, when it is configuring things post-install. Systemd has it's own profiling tools, I think, but even in 15.10, ureadahead is still being used.


Ubuntu, as well as most distros have done loads of work to boost boot times over the years. ureadahead for profiling, upstart to run startup bits in parallel, instead of one thing at a time, and other stuff has greatly reduced boot times. Now, login time, well that is a different kettle of fish, I'm gonna guess.

use bootchart to see what's going on time-wise
Getting an ssd is probably the only way to speed up booting in any truly visible manner, for most people.


reference:http://askubuntu.com/questions/68487...or-me-how-do-i

[Qqmike]

That explains
http://askubuntu.com/questions/68487...or-me-how-do-i

[Qqmike]

Oops! Same ref as yours. I had read that but omitted it in Post #4, wasn't familiar with any of it. Sorry for the trip-up.

[claydoh]

http://www.ghacks.net/2010/07/12/spe...nes-boot-time/
http://www.ubuntubuzz.com/2012/01/how-to-increasespeed-up-ubuntu-booting.html

Check the dates on these - uber-old, in Linux-years

[Qqmike]

Check the dates on these - uber-old, in Linux-years

On one, I see 12.04; the other 2010; so 2010-2011. I'm not sure that would have been such a red flag to me (without reading the readahead/ureadahead material)! Live and learn.

[claydoh]

I use a general rule of thumb of not looking at search results that are previous to the most recent LTS, or 2 years, whichever is older. Often I keep results to one year old or less.

[oshunluvr]

I use a general rule of thumb of not looking at search results that are previous to the most recent LTS, or 2 years, whichever is older. Often I keep results to one year old or less.

Yeah, I use the same general rule. Especially if it's core or system related. At the very least - further searching is in order for any info older than a year.

One area this differs is use of older, stable system parts - like bash commands for example. There hasn't been wholesale changes in bash commands in forever, so often a 7 or even 10 year old post can be useful. However, when it comes to booting - look at all the changes in the last two years: GRUB2 replaced grub-legacy and EFI was added to grub2 functionality, Kubuntu went from KDM to LightDM to SDDM, systemd replaced sysv init, and so on. Soon we will be using Wayland and Xorg will (finally and thank goodness) age out.

[Qqmike]

Look what you started, vsreeser!

[vsreeser]

Look what you started, vsreeser!

Always happy to start a debate.

[vsreeser]

I'm always trying to squeeze that last little bit of performance out of everything.
Any ideas on how effective preload is? Don't think it will have much of an impact on this machine with ssd. The other computer is only a dual core with 4gb ram and could use some help though.

[claydoh]

I'm always trying to squeeze that last little bit of performance out of everything.
Any ideas on how effective preload is? Don't think it will have much of an impact on this machine with ssd. The other computer is only a dual core with 4gb ram and could use some help though.

As your systems already do this, or a modern version of it; there may not be much left to tweak.