Have copied the Fedora Virtualbox image from another computer, failed to boot up, changed the /etc/fstab configuration file, problem resoled.
The problem shows as below screen shot, it enters into the emergency mode, after input the password, can enter the command line,
Input command:
journalctl -b
displays as below screenshot, fsck failed with error.
Check the /etc/fstab file, the error caused boot disk point to the UUID number, as below screenshot shows,
command to check the disk usage,
fdisk -l
the boot should point to /dev/sda1,
Change the /etc/fstab, comment out UUID line, added one additional line,
/dev/sda1 /boot ext4 defaults 1 2
as below screenshot shows,
Command mount -a to mount the boot disk, mount command to check the result, as below screenshot show, reboot the Virtualbox, problem resolved.
