kernel panic-not syncing: VFS: unable to mount root fs on unknown block(0,2) [duplicate]
Solution 1:
Same thing happened to me also, here's how to get it back:
First, try to boot in recovery mode:
Follow the instructions in this post.
If you manage to get to the root prompt where you can type commands, things are looking good. This should make your system bootable again:
update-initramfs -u
update-grub2
If you cannot get a root prompt at all, then get a LiveCD (the cd / usb key you used to install ubuntu should work) and boot from it. Then you have a useable system from which you can access the broken one:
Follow dilip's instructions in this post