[elrepo] Demise of Centos 8 (as we know it today) plans...

[Phil Perry]

On 18/01/2021 18:18, neil watson wrote:
> Hi
> 
> Firstly thanks for all the work you do to support older kit (eg older 
> Dell RAID controllers!)
> 
> I've had a look through the archive and can't spot any comments on the 
> widely reported discontinuation of Centos 8 from the end of the year...
> 
> I really hope that ElRepo will continue to support Centos-8-type 
> releases are that built to fill the gap - I know there are some in the 
> pipeline - as I can believe that, like Centos, other RHEL derived 
> distributions still won't have the "older" drivers that ElRepo provides
> 
> Maybe there's a place for a notice on the website / Blog explaining what 
> you are planning?
> 
> Regards
> 
> Neil.
> 

Hi Neil,

Thank you for your kind words!

We are still in the phase of trying to figure out what these changes 
mean for us and how they will impact ELRepo users.

ELRepo has always taken the stance that we support RHEL, and by 
extention that includes all RHEL compatible clones. Traditionally, this 
has included distributions such as CentOS and Scientific Linux (and any 
new clones assuming they retain compatibility), whilst other 
distributions such as ClearOS, although based on RHEL, make 
modifications to their kernel which renders many of our packages 
incompatible. This highlights just how important binary compatibility of 
the kernel is for ELRepo packages/users.

Red Hat have chosen to discontinue CentOS Linux 8 at the end of 2021. 
Red Hat have proposed CentOS Stream as it's replacement in many 
environments. Unfortunately for us, CentOS Stream, now being upstream of 
conventional RHEL releases, gets changes to the kernel which are 
scheduled for the next RHEL minor point release (their kernels diverge). 
These changes often break kernel ABI (kABI) compatibility and may cause 
ELRepo packages to no longer work.

At present, kernel releases to Stream are relatively few (maybe once per 
month) but the intention is for them to significantly increase to maybe 
weekly and potentially even daily. The kmod standard that ELRepo uses to 
package and deliver drivers for RHEL is totally dependent on the stable 
kABI that RHEL affords.

So what does this mean for ELRepo users in practice? Well, preliminary 
testing of the first kernel update to EL8.3 in CentOS Stream indicates 
that 13 out of 44 kmod packages tested were broken by the kernel update. 
I have not bothered testing the second updateas it's only going to get 
worse. It is simply not possible (for ELRepo) to deliver kmod packages 
against a constantly moving target such as the CentOS Stream kernel, and 
even if we could, these newly fixed packages would likely no longer be 
compatible with RHEL. We would be looking at a whole new repository or 
project for ELRepo-Stream and we do not have the resources to do that.

ELRepo will continue to support RHEL and compatible clones. 
Unfortunately it does not look like CentOS Stream falls into that 
category at present. I have suggested that CentOS make the conventional 
RHEL kernels available in Stream alongside the newer Stream kernels for 
those who need that kABI stability and others have proposed other 
solutions. People who need that kABI compatibility also have the option 
of rebuilding the RHEL kernel for themselves for use on Stream. But for 
now, ELRepo are unable to officially support CentOS Stream kernels. In 
reality your package may continue to work but if/when it breaks, we will 
not be able to officially support it. Hopefully CentOS will be able to 
offer a solution that allows ELRepo packages to continue to work on 
CentOS Stream.

ELRepo also offers kernel-ml and kernel-lt packages for EL8 and these 
can be used on CentOS-Stream to provide a conveniently packaged modern 
kernel (mainline or LTS) with native support for the legacy hardware Red 
Hat removed. These newer kernels may provide a convenient solution for 
some users whose hardware is not natively supported on CentOS Stream.

Phil