Need a hint about system's verbage at bootup

grigory · 02-08-2016, 06:24 PM

Hello!

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)...

frankbell · 02-08-2016, 08:15 PM

This is very strange, especially the part about ending up busy box.

What is the output

Code:

cat /etc/default/grub

A web search for "busy box ubuntu" will turn up a number of links concerning similar issues. I hesitate to pick one to recommend, as they all seem to differ in some ways, but you might have a look.

grigory · 02-09-2016, 11:08 AM

Hello! Thanks for your reply!
According to /etc/fstab that device by UUID is my Ubuntu root partition. Here's what I've got in /etc/default/grub:

Code:

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DEFAULT=0
#GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"