I have initially posted this problem on the wrong place:
https://forums.opensuse.org/showthread.php/506591-Failed-to-mount-sysroot-after-partial-failed-zypper-dup-Tumbleweed-64-bits-on-VirtualBox
I have installed Tumbleweed 64-bits on VirtualBox 4.3.26 hosted on Windows7 64 bits.
This morning, I did a zypper ref && zypper dup.
The zypper ref was OK.
The zypper dup started upgrading more than 800 packages.
But after 10 minutes, one package could not be upgrade (libreoffice).
I do not remember the reason, maybe about something unavailable on the repository…
As I do not care about libreoffice => I answered “i” (ignore).
After some other successfully upgraded packages, another one failed.
I continued to answer “i” (ignore).
And sometimes other errors, and I always answered “i” (ignore).
After this partial failed zypper dup, I attempted to redo the zypper ref but got an error about something unavailability of the repository (I do not remember the exact error message).
After rebooting my system I got a failure during the boot process.
error: unexpectedly disconnected from boot status daemon
Generating "/run/initramfs/rdsosreport.txt"
Entering emergency mode.
journalctl says “Failed to mount /sysroot.”
I do not know how to retrieve the full report file /run/initramfs/rdsosreport.txt from my VirtualBox hosted on Windows 7…
I would like to know if using a CD rescue may fix the problem (how to do?)