Summary: update-initramfs fails, can't reinstall it, can't boot server

Details: Ubuntu Server 18.04 LTS ends up with something like this from Ubuntu server crashes on boot "end trace 3b4c21cd8473b17e".

I can use a 16.04.2 .iso to offer me "Rescue a broken system" in a simple GUI:

• Network configuration succeeds
  • I can see it succeeding with "IPv6" and "DHCP" stuff although I don't know the commands it's running
• it recognizes the encrypted volume at /dev/sdb5 and lets me open it
• then lets me use /dev/ubuntuserver-vg/root as the root file system
• recognizes separate /boot partition and lets me mount it
• "grub-install /dev/sdb1 failed" if I try "Reinstall GRUB boot loader"
  • fdisk -l puts boot flag on /dev/sdb1
• lets me execute a shell with installer environment with /dev/ubuntuserver-vg/root mounted on /target
• chroot /target works
• df -h | grep boot says 236M 96M 128M 43% /boot
• apt list --installed | grep linux-image says linux-image-4.15.0-66-generic/bionic-updates,bionic-security,now 4.15.0-66.75 amd64 [installed]

If I try apt upgrade --fix-missing I get

Processing triggers for initramfs-tools (0.130ubuntu3.13) ...
update-initramfs: Generating /boot/initrd.img-4.15.0-66-generic
/usr/sbin/mkinitramfs: 1: /usr/sbin/mkinitramfs: getopt: not found
W: non-GNU getopt
update-initramfs: failed for /boot/initrd.img-4.15.0-66-generic with 1.
dpkg: error processing package initramfs-tools (--configure):
 installed initramfs-tools package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
 initramfs-tools

Edit 1:

• Thanks to @Rega, I interpreted the messages as missing commands, looked on another Ubuntu system for the package that supplied that command with dpkg -S <command> and then reinstalled that package and tried again. There were many broken packages.

After tackling as many as I could, I try to restart but get

Kernel panic - not syncing: no init found. Try passing init=option to kernel.

The only questions I see don't help:

• Secure boot is not my issue (Kernel panic - not syncing: no init found. Try passing init=option to kernel)

• I don't want to reinstall unless forced to (Kernel panic - not syncing: no init found. Try passing init=option to kernel)

• I don't have dual boot ("Kernel panic - not syncing: No init found. Try passing init = option to kernel" after installing Ubuntu with UEFI)

• I didn't use PenDrive, UNetBootin, etc. ("Kernel panic - not syncing: No init found. Try passing init = option to kernel" after installing Ubuntu with UEFI)

• I can successfully run update-initramfs -u from within chroot /target

• update-grub seems to work although it does seem to share one error grub-probe: error: cannot find a GRUB drive for /dev/sdb1. Check your device.map. done

  • I updated device.map to have one line: (hd0) /dev/disk/by-id/<my /dev/sdb hard drive>

Sorry, I don't know where is the right forum for this type of overly detailed problem.

I'm totally stuck and would love to be able to boot the server again.

Some questions I've looked at (among many others):

• My Ubuntu server 18.04 LTS won't boot up
• Ubuntu 18.04 won't boot
• Ubuntu 18.04; Won't Boot After Shutdown
• Ubuntu 18.04 won't boot after updates

/usr/sbin/mkinitramfs: 1: /usr/sbin/mkinitramfs: getopt: not found

you seem to not have getopt which is a utility that is used to parse command-line options. Check if its in a working state and reconfigure the debs.

installed initramfs-tools package post-installation script subprocess returned error exit status 1

The post-install script for the initramfs-tools package on Ubuntu systems is typically named initramfs-tools.postinst, and it is located in the /var/lib/dpkg/info directory.