Comment # 2 on bug 1186781 from Jonas Kvinge

It sounds like you are missing one of the core libraries in /lib or /lib64.
I think the kernel will boot, but you will not be able to do anything because
of missing coreutils and shell. But I don't think you will be able to fix
anything without rebooting either.
I think the system can be recovered using chroot:
https://www.suse.com/support/kb/doc/?id=000018770
If you boot up a tool like parted magic, or a live opensuse DVD, you can simply
copy, or create symbolic links the missing stuff over from /usr{bin,sbin} to
/bin or /sbin.
Worth to mention I could not chroot the system before I had created a symbolic
link from /usr/bin/sh to /bin/sh, and I think I might have copied or created
symbolic links for some core libraries too. It was really late, and I was very
tired, but I think that's what I did.
I was able to complete the zypper dup in the chroot by doing this.
The reason it didn't work for me was because I did a mistake and removed all
symbolic links in /sbin, because I was impatient and tried to copy all the
binaries intended for /usr/sbin over in /sbin from the coreutils rpm, but I
didn't take into consideration that there are more files from other packages
required in /sbin too. I was impatient because it was late and I just wanted
the system to boot right then, but I realized that it was probably a good idea
to reinstall later anyway using a different partition setup. I decided to not
spend much more time on it, so I just deleted the /boot, /, /usr, /opt and /var
partitions, only keeping the first EFI 200MB partition and /home, then created
a new ext 4 root partition (/) to replace the old, the whole point of my
previous partition setup was to keep the minimal root filesystem separate from
the rest of the system, but there is no point anymore, since you still need
/usr now anyway.
So my partition setup is now just: 1. EFI FAT 200MB, 2. 60GB ext4 system
partition and 3. ext4 /home.
I really dislike the idea of usrmerge, I like the old approach where there is a
minimal root filesystem that can boot separately. I think it would be a good
idea and fully possible if usrmerge was optional and only done on new
installations, and there it should be optional too. I don't plan on using BTRFS
either.
It would be nice if the usrmerge could be fixed to work on systems where root
and /usr are on separate partitions so that I don't have to reinstall the other
computers too.