I have installed Ubuntu 12.10 in a Western Digital external hard drive (320GB). This is a complete installation, not a live USB.

When I plug it in my HP desktop I go to the BIOS settings and boot off the hard drive, everything work perfectly as it should. Now this works on every single computer and laptop in my house (all HP), except for ONE. My HP ProBook 4530s.

When I select to boot of the USB I get the message:

error: attempt to read or write outside of disk 'hd0'

Now, I have removed the hard drive from my laptop and the external drive is the ONLY drive plugged in. Below is a screenshot of the message on the screen. After the message I navigate to ls / (as shown below):

enter image description here

After here I try to acces other folders under ls /, for example, I try to go to ls /boot to get to the grub folder. Then I get the same message as before: as shown below:

grub rescue> ls /boot

error: attempt to read or write outside of disk 'hd0'
grub rescue> _

The only folders I can access without getting the message again are /home, /run and /usr.

So how do I:

  1. Boot Ubuntu from GRUB2 (this screen) manually
  2. Set to automatically boot Ubuntu
  3. If possible an explanation for this problem


  • How old is this computer? Likelihood is, your drive is too big for the BIOS. The BIOS must support it before GRUB can.
    – user92200
    Dec 16, 2012 at 20:39
  • My computer is 6 months old and the hdd that it came with is 750gb with windows 7 pre installed. If it works with that shouldnt it work with the 320gb one. I have also booted succesfully with a netbook and an ultrabook aswell as with another desktop. The only one it does not boot with is my laptop.
    – user115064
    Dec 16, 2012 at 20:45
  • It may be BIOS USB size limits, don't quote me on this though.
    – user92200
    Dec 16, 2012 at 20:59
  • Try ’ls (hd0) ’
    – user92200
    Dec 16, 2012 at 21:03
  • 3
    Possible duplicate of How can I repair grub? (How to get Ubuntu back after installing Windows?) since both answers recommend an action that update-grub and/or Boot-Repair would perform too as described in the linked question. Apr 12, 2018 at 10:55

2 Answers 2


I have spent days messing with this and researching an answer, and I was unable to find one until today. I wanted to post the solution here because I find it unlikely that I am the only one (this question has a lot of views).

The answer for me was found here: http://www.linuxquestions.org/questions/linux-laptop-and-netbook-25/boot-problem-after-installing-ubuntu-11-04-kernel-panic-not-syncing-vfs-919143/

Booting from a LiveCD and altering grub.cfg to access the block device by name instead of UUID was the fix for me. This was temporary... in that after I updated my packages, it installed a grub update that broke it. I have been messing with the grub.cfg to try and re-fix it, now, but its progress! Hope someone can fill in the next step.

  • I'm just having this problem. Happened to me after messing around with IDE/AHCI settings in BIOS (after multiple overclocks/BIOS CMOS resets). I one hard drive and one SSD - both of them with bootloaders. I've managed to workaround the problem for now - by removing the cables from the HDD. Now system boots at least. Some sort of wrong UUID is the problem.
    – WindRider
    Feb 27, 2015 at 22:14
  • 1
    Can you provide a few more details on exactly what part of grub.cfg needs to be edited?
    – pir
    May 21, 2017 at 23:27

Sorry for the late answer, but I recently had the very same problem. I fixed it and am posting this in the hope that it may be useful to others who experience the same problem.

In my particular case it was due to a defective SATA cable. Replacing the cable fixed the problem.

More generally—by looking at the other answer and comments—I think this message may be caused by some kind of (hardware) problem when Grub is accessing the hard drive. In sorak's case, where modifying the grub.cfg file to refer to the block device by name instead of by UUID helped, it might have been the case that for some reason, the UUID could not be read anymore.

Anyway, for whoever experiences this problem, I recommend booting a live CD and using S.M.A.R.T. tools to check whether there is a problem with the hard drive, and what kind of problem. That is is what I did; this particular answer got me started. In order to interpret the S.M.A.R.T. attributes output by smartctl for a hard drive, the Wikipedia article on S.M.A.R.T. is quite useful. For me, a high UDMA CRC Error Count hinted to a defective SATA cable, and the cable indeed turned out to be the root cause of the problem.

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