I've got a dual boot W10/Ubuntu 14.04 laptop. I use GRUB2 as a boot loader. In the BIOS I chose "Legacy BIOS" option (the laptop was purchased with EUFI enabled system and W8 OEM). I don't know, maybe it's something wrong that I did during the installation or something else... Right now, I probably won't run and start changing or re-installing stuff, but at least I'd like to know what it's all about. What happens is that when I try to get into Ubuntu quite often I end up in BusyBox shell environment. Then I re-boot the machine and get to Ubuntu at last. What is even stranger to me is that it doesn't always happen. Sometimes everything is kosher and I get normally to the Ubuntu login screen (it's a desktop environment -- Unity). Now...I would present here the verbage I see on the screen while I try to get to Ubuntu, but end up in shell. sdb being the Ubuntu HDD (usually).
[ 2.978708] usd 1-1.1: string descriptor 0 read error: -22
[ 3.660632] sd 6:0:0:0: [sdb] No Caching mode page found
[ 3.660665] sd 6:0:0:0: [sdb] Assuming drive cache: write through
Gave up waiting for root device Common problems:
- Boot args (cat /proc/cmdline)
- Check rootdelay= (did the system wait long enough?)
- Check root= (did the system wait for the right device?)
- Missing modules (cat /proc/modules; ls /dev)
ALERT! /dev/disk/by-uuid/c6d0a763-50c0-4072-a72f-6286ec73709b does not exist.
Dropping to a shell!
BusyBox v1.21.1 (ubuntu...) built-in shell (ash)
(initramfs)_ (curson is blinking here)...