return to classic kernel from kernel plus

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Free1p
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Joined: 2020/10/09 10:08:54

return to classic kernel from kernel plus

Post by Free1p » 2022/01/25 17:05:47

Latest update we have update to kernel plus .
How is it possible to return to classic kernel from kernel plus .

just change in/boot/grub/grub.cong to use previous "classic" kernel and reboot ?

Is is possible to custom the kernel plus to behave like "classic" kernel ?
(something like : kernel_plus=disbale)
Thanks

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TrevorH
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Re: return to classic kernel from kernel plus

Post by TrevorH » 2022/01/25 17:28:46

kernel-plus is installed in parallel with the normal kernel and both should be on the grub menu as options at boot time.

If you want to switch away from it then disable the centosplus yum repo again then boot the latest non-plus kernel and once you are back up then you can yum remove the plus entries.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

Free1p
Posts: 14
Joined: 2020/10/09 10:08:54

Re: return to classic kernel from kernel plus

Post by Free1p » 2022/01/25 18:17:04

as usual great answer thanks TrevorH
Currently I only see the latest version is plus, and the previous "classic" version.
i need in grub.conf change the default =1 pointing to previous "classic" version and reboot . correct ?

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TrevorH
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Re: return to classic kernel from kernel plus

Post by TrevorH » 2022/01/25 18:56:04

You can change which kernel boots at boot time, no need to alter the config file. Though you can if you'd rather.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

Free1p
Posts: 14
Joined: 2020/10/09 10:08:54

Re: return to classic kernel from kernel plus

Post by Free1p » 2022/01/26 06:57:05

OK,
1. i tried to "yum reinstall <KERNEL_NUMBER>" - Skipping the running kernel .
2. rpm -qa | grep <KERNEL_NUMBER> - output is latest kernel version
kernel
kernel-firmware
kernel-headers
If i will change in grub.conf to use the previous kernel version , will it work ? (different kernel-firmware and kernel headers version )

for example:
previous kernel version - 1
new kernel version - 2

Current os started with kernel version 2

now i will set in grub.conf to use kernel version - 1
but kernel-firmware and kernel-headers are version - 2
This will work ?

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TrevorH
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Re: return to classic kernel from kernel plus

Post by TrevorH » 2022/01/26 10:44:21

1. i tried to "yum reinstall <KERNEL_NUMBER>" - Skipping the running kernel .
As I said, you need to boot a different kernel before you can remove this one.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

Free1p
Posts: 14
Joined: 2020/10/09 10:08:54

Re: return to classic kernel from kernel plus

Post by Free1p » 2022/01/26 11:33:13

OK, but will old kernel-1 version can work with new kernel-firmware-2 and kernel-headers-2 version?

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