Appendix C - Testing Point Releases

Ubuntu LTS releases are updated to a new point release version approximately three months after each intervening release – that is, 20.04.1 was released in August of 2020 (about three months after 20.04), 20.04.2 was released in February of 2021 (three months after 20.10), and so on. A similar progression will occur with Ubuntu 22.04. These updates use the kernels from the latest interim release, which can affect hardware compatibility; however, the new kernels are supported for a limited period of time compared to the GA kernel. Therefore, certification can involve testing multiple Ubuntu releases or Linux kernels:

  • The GA release – That is, the version that was released in April of the release year (2020 for 20.04, 2022 for 22.04). Ubuntu 20.04 shipped with a 5.4.0-series kernel, and 22.04 shipped with a 5.15.0-series kernel.

  • The current point release – That is, version 20.04.4, or whatever is the latest release in the series. Testing point-release versions starting with the .2 point release in addition to the original GA version serves as a check for regressions in the kernel, and may be required if the GA kernel doesn’t work on a SUT.

In theory, compatibility will only improve with time, so a server might fail testing with the original GA kernel because it uses new hardware that had not been supported in April of the OS release year, but pass with the latest kernel in a subsequent point-release. Such a server would be certified for that latest version, but not for the original GA release. If such a situation arises, testing may also be done with intervening kernels so as to determine the earliest working version of Ubuntu.

If a server fails certification with a more recent kernel but works with an earlier one, this situation is treated as a regression; a bug report should be filed and note made of the problem in the certificate request. Please notify your PE about such problems to facilitate their resolution.

Because x.04.1 releases use the same kernel series as their corresponding GA releases, testing with x.04.1 point releases is not required.

If you have problems controlling the SUT’s kernel version or installing particular point releases, then you should consult the Server Certification Team.