Using Ubuntu 20.04 on 3 different desktops with rather old CPU (Core2 Q9650, AMD FX-8320, Xeon E5-2678 v3).
The installation was made from Ubuntu Desktop ISO. The machines are updated regularly. I didn't remember doing anything special. But the kernel on these machines are upgraded from 5.4, then 5.8 and now currently Ubuntu 20.04.3 with kernel 5.11. This is OK as long as the machines run stable.
However uname -rs show different kernel versions on each machine, even if they are all up to date
Linux 5.11.0-27-generic # on Xeon machine
Linux 5.11.0-38-generic # on Core2 machine
Linux 5.11.0-40-generic # on AMD-FX machine
In particular, each time the minor version of kernel is updated, eg from 5.11.0-aa to 5.11.0-bb. The Core2 and AMD-FX machines almost always failed to get the corresponding linux-headers and linux-modules-extra. Resulting in a loss of network when rebooted. In such a case, I reboot to Grub menu, select to start with previous kernel version. Then sudo apt install the missing parts. Reboot and the machine is back to normal operation.
The Xeon machine seems to stick with 5.11.0-27-generic regardless of sudo apt upgrade I run from times to times. And this whether with secure boot enabled or not.
QUESTION 1: What is the criteria Ubuntu uses to decide which kernel version to install?
QUESTION 2: Any reason Ubuntu updater consistently failed to fetch linux-headers and linux-modules-extra when the kernel minor version is updated?
Thanks
