[CentOS] How to boot into a different kernel

Mon Feb 6 13:52:47 UTC 2012
Ljubomir Ljubojevic <office at plnet.rs>

On 02/06/2012 02:37 PM, Jonathan Vomacka wrote:
> CentOS Community,
> Is there a command to boot into a different version of the kernel? I
> believe this is setup via grub.conf but unsure. There are a few
> different kernels loaded into /boot but I want to see if there is a
> command to boot into a different kernel as a single instance or
> permanent if needed. Please advise

Without changing the /boot/grub/grub.conf:
When you start CentOS/PC, press down or up error (repeatedly until menu 
for kernel/system selection appears). Then select desired kernel.

With changing the /boot/grub/grub.conf, but manual selection:
In /boot/grub/grub.conf change:

disable hiding of the menu:

Optionally change


with larger number (number is in seconds).

With changing the /boot/grub/grub.conf, and auto-selection:

to match entry you wish to boot by default

0 = first kernel, on top
1 = second


Ljubomir Ljubojevic
(Love is in the Air)
PL Computers
Serbia, Europe

Google is the Mother, Google is the Father, and traceroute is your
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StarOS, Mikrotik and CentOS/RHEL/Linux consultant