[elrepo] Oops, updated to el7_7 on CentOS 7.6, can I revert to el7_6?

[Phil Perry]

On 09/08/2019 18:31, Seth Goldin wrote:
> Got it, thanks.
> 
> -- Seth.
> 
> 
> On Fri, Aug 9, 2019 at 1:29 PM Trevor Hemsley <themsley at voiceflex.com 
> <mailto:themsley at voiceflex.com>> wrote:
> 
>     On 09/08/2019 18:02, Seth Goldin wrote:
>>     On Fri, Aug 9, 2019 at 12:51 PM Trevor Hemsley
>>     <themsley at voiceflex.com <mailto:themsley at voiceflex.com>> wrote:
>>
>>         It's not the elrepo-release package that's the problem. You
>>         should update that again.
>>
>>
>>     I don't understand. If I want to install some package in ELRepo,
>>     but I'm using elrepo-release-7.0-4 on CentOS 7.6, won't it just
>>     fail? Shouldn't I only attempt to install
>>     with elrepo-release-7.0-3 installed if I'm still on CentOS 7.6?
>>
>>     -- Seth.
> 
>     That's the package that provides the repo definition for yum to use.
>     Without it, yum would not know about elrepo at all. If you downgrade
>     that package it does not affect the contents of that repo at all -
>     it doesn't automatically point you at some backup old version of it.
> 
>     You want the latest elrepo-release package and then on each yum
>     command until CentOS 7.7 comes out you will need to add e.g.
>     --exclude=\*nvidia\* to exclude those nvidia packages that have been
>     updated for RHEL 7.7. Or add that exclude to your repo file but then
>     you have to remember to remove it again when you do want the updates.
> 
>     Trevor
> 
> 

Looks like Seth has resolved his issues now so this may just be a 
footnote, but in the scenario Trever describes above the 
yum-plugin-elrepo package exists to prevent, for example, el7.7 specific 
packages being offered to yum for users who are still on el7.6. The yum 
plugin will automagically mask (hide) any packages requiring a newer 
kernel on systems where that newer kernel is not yet available. Then as 
soon as that newer kernel becomes available (for example, CentOS 7.7 is 
released), yum will automagically find the el7.7 specific kmod packages 
that need updating.

So, I would strongly recommend that non-RHEL / CentOS users install the 
yum-plugin-elrepo package.

Phil