Yesterday evening, I don't know what happened but my system (Ubuntu 13.10) didn't boot. Since then I tried many times but the same issue as I explain below.
See I boot my system. GRUB menu comes; I select ubuntu (to boot); then as normal the Ubuntu symbol comes but it takes a long time there & then prompt appears in a terminal with the messages as shown below:
Code:
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/da5b7ccd-e161-4460-4012-1b54eaf31faa doesn't exist.
Dropping to a shell!
BusyBox v1.20.2 (Ubuntu 1:1.20.0-8.1 ubuntu1) built-in shell (ash)
Enter 'help' for a list of built-in commands.
(initramfs)_
From the message, I felt to check whether the root device (/dev/sda5 is root partition in my case) is O.K. or not.
I booted live usb of Ubuntu 14.04.1 (that I downloaded yesterday). I mounted all the partitions of the hard-disk installation having Ubuntu 13.10 (/home, /, /var/, /boot, /tmp). To my surprise, root partition didn't contain anything but others had data.
root partition was empty !!!!
As the above output mentioned "ALERT! /dev/disk/by-uuid/da5b7ccd-e161-4460-4012-1b54eaf31faa doesn't exist", I thought to check if that's the UUID of the root partition & that partition is what it is saying that doesn't exist!
Code:
ubuntu@ubuntu:~$ sudo lsblk -o name,mountpoint,label,size,uuid
NAME MOUNTPOINT LABEL SIZE UUID
sda 111.8G
├─sda1 System Reserved 100M 6E60F4D460F4A3CD
├─sda2 c_drive 31.2G 0E441C8F441C7BA1
├─sda3 d_drive 36.9G 100EECEB0EECCB34
├─sda4 1K
├─sda5 root 14G 5dd68245-345c-44f4-8c22-a6779472e388
├─sda6 boot 314M 84e87924-cc93-45d9-82d3-39a925110a2b
├─sda7 2.1G
├─sda8 var 1.9G f607795c-5f8c-4c14-a4d8-2d0e71d0319a
├─sda9 tmp 1.9G a3f24d77-7c45-4a3d-b153-478d8261c338
└─sda10 home 23.7G 735de76f-65f3-4963-ad0e-44a4a2b34e97
sdb 1.9G
└─sdb1 /cdrom 1.9G bc426250-9c5d-4d9e-8b15-43bafa7bb4ac
sr0 1024M
loop0 /rofs 952M
ubuntu@ubuntu:~$
And I find that the UUID of the root partition is not that what the system mentioned while booting. To reconfirm I checked the listing of the directory /dev/disk/by-uuid. (This is the directory that the above output mentioned in "ALERT")
Code:
ubuntu@ubuntu:~$ ll /dev/disk/by-uuid
total 0
drwxr-xr-x 2 root root 220 Jul 29 22:35 ./
drwxr-xr-x 6 root root 120 Jul 29 22:35 ../
lrwxrwxrwx 1 root root 10 Jul 29 22:35 0E441C8F441C7BA1 -> ../../sda2
lrwxrwxrwx 1 root root 10 Jul 29 22:35 100EECEB0EECCB34 -> ../../sda3
lrwxrwxrwx 1 root root 10 Jul 29 22:35 5dd68245-345c-44f4-8c22-a6779472e388 -> ../../sda5
lrwxrwxrwx 1 root root 10 Jul 29 22:35 6E60F4D460F4A3CD -> ../../sda1
lrwxrwxrwx 1 root root 11 Jul 29 22:35 735de76f-65f3-4963-ad0e-44a4a2b34e97 -> ../../sda10
lrwxrwxrwx 1 root root 10 Jul 29 22:35 84e87924-cc93-45d9-82d3-39a925110a2b -> ../../sda6
lrwxrwxrwx 1 root root 10 Jul 29 22:35 a3f24d77-7c45-4a3d-b153-478d8261c338 -> ../../sda9
lrwxrwxrwx 1 root root 10 Jul 29 22:35 bc426250-9c5d-4d9e-8b15-43bafa7bb4ac -> ../../sdb1
lrwxrwxrwx 1 root root 10 Jul 29 22:35 f607795c-5f8c-4c14-a4d8-2d0e71d0319a -> ../../sda8
ubuntu@ubuntu:~$
So, what's that alert - "
ALERT! /dev/disk/by-uuid/da5b7ccd-e161-4460-4012-1b54eaf31faa doesn't exist"? What doesn't exist?
Just to troubleshoot: Yesterday before the issue happened, I'd booted live usb of Ubuntu 14.04.1. Then I mounted the partitions of Ubuntu 13.10 of my hard disk. Can the problem occur had I not unmounted them before shutting down my system or was it that the system wasn't properly shutdown !! I don't know what had happened.
I was going to install Ubuntu 14.04.1 on my laptop to get the things working back but thought to see if it it can be resolved now only because I never expected my system to get broken this way. I'd earlier faced issues with booting but that was bootloader thing that I learned to resolve; this issue I want to get it resolved too so that suppose next time anything like this happens, I do have the solution. It was fortunate that I'd bootable usb having Ubuntu 14.04.1 beside me this time which I booted up (live install) & writing this Q from there.
