Re: Retaining Older Kernels After Image Update

[Pascal Hambourg <pascal@plouf.fr.eu.org>]

Reco a écrit :
>  Hi.
> 
> On Wed, Aug 06, 2014 at 10:06:46AM +0200, Pascal Hambourg wrote:
>> Marc Auslander a écrit :
>>>
>>> I just manually copy the four files in /boot associated with the
>>> working kernel.  I append -knowngood to get new names.  update grup
>>> happily makes boot entries for them.
>>
>> What about the kernel directory in /lib/modules which contains the major
>> part of the kernel ?
> 
> Kernel modules that are needed for the boot process itself reside in the
> initrd, and he copies that.

For the *early* boot process. I.e. mounting the root filesystem and not
much else.

> Kernel modules that live in /lib/modules are loaded after root
> filesystem is mounted and init is started. As long as kernel's ABI isn't
> changed they should load successfully.

But this method provides no backup if the update causes a regression in
one of these modules which may break a major fonction of the system.