How To Install Old CentOS Kernel or Packages (and Few Reasons Why You Want It)
When we update packages in Linux OS such as CentOS and RHEL, normally the update process will pull latest packages from the repository. But sometimes the latest is not what we want, for example there is a support page in Citrix website - https://support.citrix.com/article/CTX200094 that describes that sometimes when updating we get version/release that not supported by the vendor (in this case, Citrix XenServer). In my case I am trying to check whether LKRG (the Linux Kernel Runtime Guard) could detect one of my servers that got hacked by some rootkit, but as I will show I got baffled by missing kernel rpm packages. Background (Why do you want old Kernel Devel package?) Some hacker installed rootkit in my server, and I want to do some analysis on it. I want to use a server that is more idle than the hacked server, but the kernel version differs and seems that linux kernel module is specific to the kernel version. So I need to install the specific version that is equal to the hacked...