Multiple OS on boot


(Stephan Koenig) #1

When I reboot my PBX, I am offered two OS versions. No idea how that happened. The first one (picked by default) does not work, it stops with an error message.

image

The second one works fine. But I need to be around to select it.

I tried to find the settings for it, but I am lost.
/boot/grub/ is empty.
/boot/grub2/ has a gub.cfg, but it says:
DO NOT EDIT THIS FILE
It is automatically generated by grub2-mkconfig using templates
from /etc/grub.d and settings from /etc/default/grub

Can’t find the settings in those files.


(Jared Busch) #2

try

yum reinstall kernel*

(Stephan Koenig) #3

Thank you! That worked!


#4

I also see more than one at boot (like StephenK above), however, my PBX auto-selects the current one after n-secs & so doesn’t cause an issue.

@sovani - If I run ‘rpm -qa | grep kernel | sort’ I can see multiple Kernels installed on my PBX (I assume from system upgrades along the way).

image

Is it advisable & safe to remove previous versions & if so, would I have to remove each one individually (eg. yum remove [kernel1] [kernel2] etc…), or is there a command to remove all except the current one ?

Also, my understanding is that the command you offered above reinstalls all existing kernels. Do you mind explaining how that fixed Stephen’s issue - Did it reinstall the kernels & reset the auto-select timer (like on my PBX). So in other words, he still has the 2 kernel boot options, it just auto-select now, or have I mis-understood ?


#5

https://www.tecmint.com/delete-old-kernels-in-centos-rhel-and-fedora/

of course you would need to remove any broken kernels before you pare down the working ones.

As to the default boot


#6

Helpful articles, thanks. I guess the ‘package-cleanup’ command from yum-utils is what I was asking about.

With regards to ‘removing broken kernels 1st’, how do I verify if any are broken ? (I assume the current one I’m using isn’t by the fact I’m booted to it)


#7

If you can boot the kernel successfully there is a fair to good chance it isn’t broken :wink:

(sorry , couldn’t resist that )


#8

No problem.

My system appears to boot & run stable on the current, most recent kernel & so I assume I can safely remove some of the earlier ones.


#9

There is no need to do that unless the partion holding /boot is getting too full, concentrate on more important things


#10

I guess you mean this guy ?

image


#11
df /boot

Would give you your answer

du -h /boot/*

more info