Arch Linux

xtian

Member

Registered: 2013-08-25

Posts: 179

[solved] Please explain the significance of "Downgrade Kernel step

I've noticed my laptop is running hotter. After finding this recent post, Fan always on with 3.18.2-2, I'd like to downgrade my kernel to `linux-3.17.6-1`. Reading the instructions Downgrading Packages in the Wiki, I don't understand the significance of this line:

"If you are unable to boot after a kernel update, then you can downgrade the kernel via a live CD."

This assumes a scenario (upgrade kernel > non-bootable system). And suggests its permissible to fix this by booting from live media. But is it necessary to boot from live media when downgrading the kernel?

Last edited by xtian (2015-02-05 16:43:33)

Head_on_a_Stick

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From: The Wirral

Registered: 2014-02-20

Posts: 9,003

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Re: [solved] Please explain the significance of "Downgrade Kernel step

No.

We're up to 3.18.5 ATM -- have you tried that?

The LTS kernel is also an option.

---

Jin, Jîyan, Azadî

drcouzelis

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From: Connecticut, USA

Registered: 2009-11-09

Posts: 4,092

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Re: [solved] Please explain the significance of "Downgrade Kernel step

"If you are unable to boot after a kernel update, then you can downgrade the kernel via a live CD."

This assumes a scenario (upgrade kernel > non-bootable system). And suggests its permissible to fix this by booting from live media. But is it necessary to boot from live media when downgrading the kernel?

If you install a new kernel package and then your computer doesn't boot, then you can use an Arch Linux live CD to revert to the last kernel package that you know worked. (You can also do anything else you need to do to fix the installation from the live CD.)

If you CAN boot your computer, then you don't need to use the live CD (of course).

Last edited by drcouzelis (2015-02-05 15:22:11)

karol

Archivist

Registered: 2009-05-06

Posts: 25,440

Re: [solved] Please explain the significance of "Downgrade Kernel step

If you can't boot from your hard drive, try using liveCD/liveUSB. If the issue seems to be with the kernel you're trying to use and you have multiple kernels installed, try using another kernel instead.

xtian

Member

Registered: 2013-08-25

Posts: 179

Re: [solved] Please explain the significance of "Downgrade Kernel step

No.
We're up to 3.18.5 ATM -- have you tried that?
The LTS kernel is also an option.

That's what I needed to know. The most recent post in the linked thread reports 3.18.5 did not fix the problem, so I didn't think that was a good use of my time. There seems to be consensus in the thread downgrading to 3.17 is the way to go. Since I've never attempted a downgrade before, I thought it was a good time to learn. And the instructions are super simple. If it turns out I can't reboot, it will be easier to have these files on a usb stick, so I'm collecting the necessary files, just in case.

The instructions on the Wiki should reflect this, so I'll continue the thread about the wording in the wiki over there. Thanks all.

Last edited by xtian (2015-02-05 16:44:06)