Elilo works with UEFI.

Correct, but it is not developed any more. One day it will not build any more without patching. I recommend rEFInd over ELILO and GRUB-2.

Hya

Thanks for your comment.

As I cloned HDD, I guess UUID stays same (that's what wikipedia says).

Yes, I also think that lilo and grub don't get along. I do not know why I ran into such a situation. I know how to install MBR (sbin/install-mbr), but do not know how to remove it. I thought grub would overwrite it, if lilo is purged, which turned out to be false.

+++

I found another problem. It looks like init.d (or whatever, scripts on boot) is slightly screwed up. Probably, it is related to the network problem described above.

I will update.

cheers

Might check with P. Volkerding - He seems to have taken over maintence of lilo (and I believe elilo) for Slackware.

The problem I've had with grub2 is that it won't accept being put on a partition anymore - or at least, not easily. The rest is just that I dislike deliberate complications for no good use. Grub2 is becoming its own operating system, rather than a boot for operating systems.

Hya,

(about lilo discussion)

Yes, I wanted to proceed with elilo. However, it was missing in debian stretch repo, when I checked the other day. If anybody maintains it, I definitely go back to lilo.

cheers

Hya,

Update.

For some reason, network setting (udev setting?) was not conserved. (thanks to this thread.)

Several other minor troubles include
slow application startup, weird mouse cursor movement (resolved after reboot),
display name change (VGA1 -> DP3; affected xrandr script for desktop position)
slight decrease of available memory (affected slurmd)

++ added on edit
This thread explains interface name change.

So far, good.

One point I noticed during this troubleshooting, loose sata cable can manifest some weird situation.

Hya,

Update,

The problem, random freeze and font error, does not occur last couple of weeks. I here declare that troubleshoot itself is done.

Following issue accompanied, most of which were not investigate deeply.
interface name, lilo/grub, MBR/efi.
My impression is that they are related.