Dear Experts

System, 4 Debian amd64 penguins. testing, slightly differernt configuration.

An idiot (=me) did something silly.

After system upgrade (apt-get update, apt-get dist-upgrade), new kernel (6.6.15) compiled. (make oldconfig; make) without error.
I forgot to "make install" before update-grub

Something starts to go wrong.

One penguin did not reboot, but bios (UEFI ?) screen shows up, and unable to boot Debian image (it shows up in menu, though). The others boot in old kernels. I was able to streighten up three others, but not the one which did not reboot.

With USB sitck (installer image, kernel 5.x era, but it worked), booted into rescue mode, then execute shell. HD is not mounted on /target, as screen reads.

Is there any other way to execute "make install"?

Quite a while ago, I forgot to run "lilo" after "make install". I was able to recover with rescue mode, but if I remember correcct, there was "mount hard disk partition" or something, which I do not find today.

I will appreciate any input.

cheers

Don't you still have the old kernel? Hold down shift to get to grub menu and select the last working kernel.

compilation (make oldconfig; make) will not change anything in grub or lilo and in the boot sequence.
make install will install the new kernel, but probably you will need make modules_install too, otherwise the new kernel won't be able to find its modules.
Yes, as it was mentioned you need to be able to use advanced menu and boot the previous/old kernel.

Thank you for your prompt replies.

Yes, I do have old kernels, but for some reason, this one does not boot, (other three did, so rescued) grub screen does not show up, only bios screen.

Yes, I also forgot make modules_install. I was able to rescue other three easily.

I think that if only HD is mounted, it could be rescued. How?

cheers

the usual question: do you have a reliable backup?
Sometimes a full reinstall is faster than recovering, but it depends on the actual situation, the content. You have 3 other similar hosts, you may try to use them to restore a few files or probably a partition too. But without details hard to say more. Exactly what went wrong, what's happening....

Yes, I do. I have full data backup, triplicate.

No, I do not. Several config files and setting files are not. (node dependent ones.) Dead one is a front end, so history... It should not be difficult to rebuild, but rescue mode would be nicer.

As currently I have no access to logs, I will take disk drive out and see what happened.