Interesting thread. I tried to optimize with profiling the booting process of my rig (Intel G45 mainboard, E8500 Core 2 Duo downclocked @ 2.53 Ghz, Western Digital Raptor 74GB 10k rpm) on Ubuntu 9.10 Karmic Koala (development-testing) and to track the changes with Bootchart:
Without profiling: 12 seconds
With profiling: 12 seconds
With profiling and --background read-ahead: 12 seconds
It looks like I hit a wall, though with optimizations, according to Bootchart, I/O transfer speed seems to have increased and Hard Disk usage maxed out. Probably the boot time decreased by less than one second.
This is a video of a cold-start complete bootup of my pc before profiling: http://www.youtube.com/watch?v=3wj6n66d9b4
After profiling boot time went from 25s to 30s(according to bootchart.
The bonus hack seems to be enabled by default as there is no "--background" anywhere in the file.
Since i have only 256MB RAM I considered disabling readahead altogether. The "boot" file was already empty however the "desktop" file was loaded with useless stuff like:
I'm running Jaunty 9.04 which was upgraded from 8.10 using aptitude safe-upgrade. Googling yields bug reports on Intrepid having an overenthusiastic readahead file and preloading stuff like screensavers.Code:
With readahead disabled boot time increased to 31s... :confused:
Is there any way i can get it back to 25s? :(
EDIT: I purged readahead and reinstalled, got it down to 26s.
I have a OCZ vertex and an i7 920. Jaunty boots in 15sec according to bootchart with no profiling (I am using preload, haven't checked if that changing boot speed).
After profiling this went up to 27sec (purging readahead fixed it), so it seems fairly pointless for those of us with SSDs.
Id like to save boot up time but ive got a problem...
when my grub loads i press ESC as you said and nothing seems to happen, after some time itll just boot up normally, ignoring what i pressed.
Confirm please - this is now invalid (no longer applicable) for Lucid and Maverick?
If you are using Lucid Lynx and you don't have another operating system on your computer, to show up your grub, you should edit the follow archive:
sudo gedit /etc/default/grub
It shows your grub configuration, find the following line and comment it with this simbol '#':
Save this new configuration, and run the following command in your terminal:
##To come back to the default configuration, uncoment the line and run again:
I hope it helps, but with the default grub in Lucid Lynx 10.04 the line begining by 'kernel' doesn't exist. Then were to put 'profile'?
spiffing, if it works..
But we shoudl only be rebooting with kernal updates ;) come on folks, uptimes important, not boot-time* ;)
Quite a long-running thread!
Looks like the technique mentioned in the following article accomplishes pretty much the same thing:
Ubuntu boot times have gotten a lot better since this thread started -- so much so that I don't think I'll bother using "profiling." But, fascinating stuff!