[qubes-users] new xen kernel 5.xx

I have still instabilities with the xen kernels 5.x (sudden system
freeze). I also have a small /boot and hold only the last 3 kernels.
They are right now:

vmlinuz-4.19.155-1.pvops.qubes.x86_64
vmlinuz-5.4.78-1.qubes.x86_64
vmlinuz-5.4.83-1.qubes.x86_64

I would like to mark the (for me very stable) kernel 4.19.155 as "do not
erase while updating" and remove the (for me) useless kernel
vmlinuz-5.4.78-1.qubes.x86_64. How can I do that, please? I fear to
make a mess when just "playing around". I also want to keep 5.x kernels
for appVM's (they work well). Thank you!

I have still instabilities with the xen kernels 5.x (sudden system
freeze). I also have a small /boot and hold only the last 3 kernels.

I can (outside of Qubes OS) trigger a kernel freeze when the kernel starts swapping on a thin-provisioned LV. I think I wrote that to this list some time ago. You could also find some details at kernel.org's bugzilla.

They are right now:

vmlinuz-4.19.155-1.pvops.qubes.x86_64
vmlinuz-5.4.78-1.qubes.x86_64
vmlinuz-5.4.83-1.qubes.x86_64

I would like to mark the (for me very stable) kernel 4.19.155 as "do not
erase while updating" and remove the (for me) useless kernel
vmlinuz-5.4.78-1.qubes.x86_64. How can I do that, please? I fear to
make a mess when just "playing around". I also want to keep 5.x kernels
for appVM's (they work well). Thank you!

I think you'll have to find out what actually makes your kernel freeze (if it freezes at all).

haaber:

I have still instabilities with the xen kernels 5.x (sudden system
freeze). I also have a small /boot and hold only the last 3 kernels.
They are right now:

vmlinuz-4.19.155-1.pvops.qubes.x86_64
vmlinuz-5.4.78-1.qubes.x86_64
vmlinuz-5.4.83-1.qubes.x86_64

I would like to mark the (for me very stable) kernel 4.19.155 as "do not
erase while updating" and remove the (for me) useless kernel
vmlinuz-5.4.78-1.qubes.x86_64. How can I do that, please? I fear to
make a mess when just "playing around". I also want to keep 5.x kernels
for appVM's (they work well). Thank you!

I think I was able to keep an older version around before by (very carefully) uninstalling the middle version from dom0, as it keeps 3 copies by default. I believe I used dnf and specified the exact version to remove.

Is there another way to boot to an older kernel rather than boot from other media and edit xen.cfg?