[lanstin]

In 2017 I led a (painful) project to migrate from RHEL5 to Ubuntu 16. Since then, it has been pretty easy to go to 18 then 20, soon 22. The previous migration was in 2010 and was from RedHat 6 (not RHEL) to RHEL5. These projects were for projects that are "ghost deprecated" in that not much time is spent in talking about them but they are critically important to the business, as profit centers and cost drivers, but not the new flashy stuff. So we saved $10s of millions of dollars in hardware savings mostly due to the improved schedulers in 4.0.x series of kernels compared to 2.6.28 kernel. The same image became the basis of the containerized version that was rolled out a bit later.

[donkeybeer]

22 might be difficult depending on what you use from Ubuntu 's repositories; they are converting apt apps to snaps.