Disable UEK repositories on Oracle Linux 6.9

Question

I have lots of machines running the Red Hat compatible kernel and this has not been as issue before. However, the latest default behaviour appear to be that the repository configuration file is updated with UEK4 enabled on "yum update"

The next "yum update" will install UEK4 and set it as the default kernel. Any problems caused by this, will be discovered when the next boot fails.

It would be best if I could pre-emptively disable the UEK4 repository, before the repository file is even updated by yum.

The default yum repository configuration file /etc/yum.repos.d/public-yum-ol6.repo installed with OL6 Update 9 contains references to variables $uek, $uek3 and $uek4 suggesting that the UEK repositories can be disabled in some central way.

[public_ol6_UEKR4]
name=Latest Unbreakable Enterprise Kernel Release 4 for Oracle Linux $releasever ($basearch)
baseurl=http://yum.oracle.com/repo/OracleLinux/OL6/UEKR4/$basearch/
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle
gpgcheck=1
enabled=$uekr4

Where might yum be getting these values?

Can I set them somewhere, thus preventing a "yum update" from inadvertently changing the kernel and messing things up?

Answer 1

I realise that this is a pretty old question and you may no longer care about the answer but after some digging around (well a lot of digging, I wanted to know the 'right' way to do it too!) I found that in /etc/yum/vars you will find files that hold the values for these variables. So to disable uekr4 you simply change the contents of /etc/yum/vars/uekr4 from 1 to 0

This is how I figured it out and is from the RedHat website:

To define a custom variable or to override the value of an existing one, create a file with the same name as the variable (without the “$” sign) in the /etc/yum/vars/ directory, and add the desired value on its first line.