Webstack - Grub Bootup Management

Having updated the main server without taking care to check just what openSUSE was loading, I needed to drop back to the previous kernel. SUSE has this habit of pushing changes such as a jump of kernel version without any fanfare so V7 appeared perhaps before I was ready, along with PHP8.5 which is a lot more of a problem. Having previously had to roll back because the desktop machine lost it's network capability, selecting from the startup menu is not a problem, but the main server was working a little faster that made that practical, so I temporarily disabled the timeout, but also had a play with manually setting the default kernel just in case I did need that. I've also protected the last V6 build from deletion.

Set back to booting latest/default
grub2-set-default 0
grub2-mkconfig -o /boot/grub2/grub.cfg
# means "boot the first entry" which will be the latest kernel going forward — so next time Tumbleweed updates the kernel it boots automatically without needing manual intervention.

Restore timeout nano
/etc/default/grub
# Change GRUB_TIMEOUT to -1 to disable auto load timeout. 

Then update grub2
grub2-mkconfig -o /boot/grub2/grub.cfg

# What is currently set as default
grub2-editenv list

# List all available boot entries
awk -F' '/menuentry / {print $2}' /boot/grub2/grub.cfg

# List kernels installed
rpm -qa kernel-default | sort

# Set specific kernel as default (use full string from awk output)
grub2-set-default "full entry name here"
grub2-mkconfig -o /boot/grub2/grub.cfg

Just to be on the safe side, I've updated the /etc/zypp/zypp.conf file so that 6.19.12-1-default remains available going forward. A bit of belt and braces
The location of config files has been part of the recent fun, and the installed zypp.conf is located in /usr/etc/zypp/zypp.conf and I copied that to /etc/webstack for inclusion in the setup process
updating the line multiversion.kernels = latest,latest-1,running,6.19.12-1-default does the business