If you make a OS Upgrade on a older PC the Bios cant boot the new OS cause Ubuntu changed the Compression Type of initramfs tools to “zstd” which older Bios cant boot.
Howto fix:
- On UPGRADED NOT REBOOTET OS edit “/etc//initramfs-tools/initramfs.conf” CHANGE COMPRESSION = gzip !!
- then “sudo update-initramfs -u -k all” and “sudo update-grub”
- CHECK the installation of cryptsetup-initramfs this is very OFTEN MISSING by UPGRADE DEPS!
- now reboot..
If your OS is broken and you use LUKS as Laptop Protection, plugin a USB Stick with same Version of Upgraded Ubuntu and boot the Laptop to Live Try Mode
Howto fix on Luks:
- Open Terminal and enter “sudo -s” to be root
- cryptsetup luksOpen /dev/sda3 sda3_crypt
- mount /dev/mapper/ubunut–vg-root /mnt
- mount /dev/sda2 /mnt/boot
- mount /dev/sda1 /mnt/boot/efi
- for i in /dev /dev/pts /proc /sys /run; do mount -B $i /mnt/$i;done
- chroot /mnt
- nano /etc//initramfs-tools/initramfs.conf “here set COMPRESS=gzip bug is zstd”
- update-initramfs -u -k all
- update-grub
- reboot ..
- the OS should now work..
Ubuntu has made a big mistake to change the compression type and to break Systems i checked size between gzip and other Compression Types the Size was near same of initramfs. This is a “No need Bug”.