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While reading about speeding up Linux, particularly the boot process I found that concurrency is suggested for multiple core PC's. It appears that this setting was easily achieved in legacy GRUB, however I could not discover how to achieve this in GRUB2. My system:

grub customizer ver 3.0.4
Ubuntu 12.10 session fall back   3.5.0-24-generic
HP desktop with Intel iCore 7 3.2Ghz
12 Gb ram
1 Tb hdd
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up vote 4 down vote accepted

You probably found someone stating to add concurrency=shell in GRUB2. This was deemed obsolete as of 12.04

See /etc/init.d/rc and change concurrency to makefile. Remarks and option in that file:

# Specify method used to enable concurrent init.d scripts.
# Valid options are `none` and `makefile`. 
# Obsolete options used earlier are `shell` and `startpar`.
# The obsolete options are aliases for 'makefile' since 2010-05-14.

If you have none set it to makefile.

By the way: install bootchart first, create a bootchart, edit rc and make a new bootchart if you want to see if it improves boot time.

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Apparently the default 12.10 installation is concurrency=makefile since both my installations were set that way. I assume that this indicates grub2 automatically adjusts for multiple cores – pfeiffep Mar 18 '13 at 17:35
it should. but if you can proof it all the better ;) – Rinzwind Mar 18 '13 at 17:40
Thanks a bunch! – pfeiffep Mar 18 '13 at 17:56

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