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I am trying to install Ubuntu 12.10 for quite some time, and passing hurdles one by one. Now I am in a situation as follows.

I have got a PC and 10 GB HDD which will be totally dedicated to Ubuntu so no option of Wubi and dual boot.

I was trying to install from DVD, but it is getting stuck at "Out of frequency" error. So I had to adapt for USB boot option. But my PC is USB non bootable, so workaround is "Plop Boot Manager". So I am doing the installation procedure as follows:

  1. starting from a CD drive which is having plop installed.
  2. opting for for USB boot in plop options.
  3. booting begins from USB.
  4. monitor eventually gives "out of frequency" error
  5. press Shift+Alt+F1 to get the terminal.
  6. open the grub with sudo nano /etc/default/grub.
  7. do necessary changes.
  8. sudo update-grub.

Now here I am getting error as follows:

/usr/sbin/grub-probe:error:failed to get canonical path of /cow.

My system is

P4 3.06 GHz, 1 GB ram , 10 GB HDD without an OS, monitor CRT lg StudioWorks (7 years old). Mobo Mercury P4 266a NDMx (865 equivalent). The whole system is perfectly in working condition under XP, but it is USB non bootable, and all other devices working perfectly.

What should I do next?

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Does your computer have the Recommended Minimum System Requirements to run Ubuntu? I have had problems installing 12.04 to machines with less than 1GB RAM. –  C.S.Cameron Feb 14 '13 at 5:49
Yes ,Now I have added my system specification to question. –  ulkaNCST Feb 14 '13 at 7:56
askubuntu.com/questions/207663/… might be worth a try. –  Rinzwind Feb 14 '13 at 7:59
First mount your hard drive to some folder, say /mnt and then chroot to /mnt. –  green7 Feb 18 '13 at 3:44

4 Answers 4

After booting from the 14.04 live CD I was able to work around this problem by running update-grub chroot'ed to the grub partition. Perhaps as simple as:

sudo mount /dev/sda /mnt
sudo chroot /mnt
sudo update-grub2

In my case the grub partition was a stand-alone boot partition with no system installed, so I had to bring in most of the system to the chroot environment first:

mkdir /mnt/chrootdir
mount /dev/sda1 /mnt/chrootdir
for dir in proc dev sys etc bin sbin var usr lib lib64 tmp; do
    mkdir /mnt/chrootdir/$dir && mount --bind /$dir /mnt/chrootdir/$dir
chroot /mnt/chrootdir
update-grub2  # inside chroot

Substitute /dev/sda1 in that recipe with whatever partition you installed GRUB on.

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You sound also use this command enter from tty2:


and then enter:

  hash -it / -d

could might work fine.

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now it works ?! --- hash -it ... is funny ... now you hash /cow ?! ;) –  dschinn1001 Jun 11 '14 at 13:17
  1. Find A Windows Machine
  2. Download LiLi Creator
  3. Create The Ubuntu 12.10 Disk
  4. Make sure to Enable Persistence


Usually, on a live CD or Live USB key, all modifications are discarded when you reboot. The persistence allows you to keep your preferences and data even after reboot. The data are stored in a special file called casper-rw (for Ubuntu) and overlay-USBLABEL-UUID (for Fedora). This is a completely transparent process for the user. Usually, 300 MB are enough to install some software but you can use more. 5. See This Post: cannot mount /dev/loop1 on /cow

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It is the update-grub command which will give you the error when using it from a live cd. I faced with a similar situation when i was doing a grub rescue. The problem you have is that update-grub and grub-install commands do not work directly under live cd (I don't know why). So, you have to go to /usr/sbin where the commands are located and execute them from there (i.e ./update-grub).

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No, you have to mount the hard disk and chroot into it, like @green7 said. –  psusi Apr 2 '14 at 18:27
my method also works. try it. its simpler –  aveemashfaq Apr 4 '14 at 12:32
You don't have a method. /usr/sbin is on the path already so there is no need to cd there. You can't run grub-install and update-grub directly from the live cd ( as you noted ) because it tries to set up grub to boot the current system, which would be the live cd, rather than the os installed on the hard drive. –  psusi Apr 4 '14 at 14:00
This, of course, doesn't work. You get the "can't get cannonical path of /cow" error. And the stuff about cd-ing to /usr/sbin... oh boy. –  dan3 Apr 13 '14 at 12:37
try it people. it worked for me all the time –  aveemashfaq Apr 13 '14 at 13:09

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