i had win7 and ubuntu 13.04 in my laptop. but somehow window7 corroupted and ubuntu working. then i reinstall window and afetr that i am not able to see ubuntu in booting option.

i inserted live ubuntu-cd. i run some commands and mount the linux drive as sda6. now found grub in boot folder. but after that not able to update or configure Grub.

so not able to see the dual boot option. pl. help

Hi,

Windows 7 wrote its bootloader over your GRUB in MBR, assuming it is MBR and not UEFI; please correct me if I'm wrong.

Since you boot the live CD and mount your Linux filesystem, half the job is done already. Now you simply have to chroot into your filesystem and install GRUB back to the MBR.

Let us say you mount sda6 at /mnt/ubuntu (this is just an example mount point, you can replace this with your own mountpoint):
Then you exit the chroot environment and reboot. The grub-mkconfig line will generate a new grub.cfg which contains entries for both Unbuntu and Windows 7. That should do it.

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get this error message after running the command:

sudo: unable to resolve host ubuntu /usr/sbin/grub-probe: error: failed to get canonical path of /dev/sda6

Ok, then maybe, some more steps to get the filesystem right:
If anything goes wrong, please post the command along with the error message.

All the best.

sir,
i m using the following commands to start and mount the sda6. am i mounting the right partition? i am not sure. all the commands work as u mentioned in last post except the last one.grub-install /dev/sda.

ubuntu@ubuntu:~$ sudo su
root@ubuntu:/home/ubuntu# sudo fdisk -l

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0xc3ffc3ff

Device Boot Start End Blocks Id System
/dev/sda1 * 2048 206847 102400 7 HPFS/NTFS/exFAT
/dev/sda2 206848 204797951 102295552 7 HPFS/NTFS/exFAT
/dev/sda3 204799998 511997951 153598977 5 Extended
Partition 3 does not start on physical sector boundary.
/dev/sda4 511997952 976771071 232386560 7 HPFS/NTFS/exFAT
/dev/sda5 204800000 208797695 1998848 82 Linux swap / Solaris
/dev/sda6 208799744 511997951 151599104 83 Linux

Disk /dev/sdb: 4098 MB, 4098883584 bytes
2 heads, 63 sectors/track, 63536 cylinders, total 8005632 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x002aa5b9

Device Boot Start End Blocks Id System
/dev/sdb1 * 64 8005631 4002784 b W95 FAT32
root@ubuntu:/home/ubuntu#

Does the grub-mkconfig command work? If yes, please post the output of grub-mkconfig line and grub-install line.

the output of grub-mkconfig is:

root@ubuntu:/# grub-mkconfig -o /boot/grub/grub.cfg
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-3.8.0-19-generic
Found initrd image: /boot/initrd.img-3.8.0-19-generic
Found memtest86+ image: /boot/memtest86+.bin
Found Windows 7 (loader) on /dev/sda1
don[/I][/I]e

the out put of grub-install is:

root@ubuntu:/# grub-install /dev/sda1
/usr/sbin/grub-bios-setup: warning: File system `ntfs' doesn't support embedding.
/usr/sbin/grub-bios-setup: warning: Embedding is not possible. GRUB can only be installed in this setup by using blocklists. However, blocklists are UNRELIABLE and their use is discouraged..
/usr/sbin/grub-bios-setup: error: will not proceed with blocklists.

Ah, now we have all the relevant information to better address the problem.

grub-mkconfig sees all your installs and adds an entry for them in configuration file /boot/grub/grub.cfg. As you can see, it also detects Windows 7. So, we are not far from a working system. The final step would be to install the bootloader in the MBR of your hard disk, which is designated by /dev/sda.

And, you can see that you are trying to install the bootloader in /dev/sda1, which does not work since its filesystem is NTFS. So, please correct that. You don't need to run grub-mkconfig again since the config file has been generated already. You just change /dev/sda1 in the above to /dev/sda and it should work.

The output of grub install /dev/sda is:

root@ubuntu:/# grub-install /dev/sda
/usr/sbin/grub-bios-setup: warning: this LDM has no Embedding Partition; embedding won't be possible.
/usr/sbin/grub-bios-setup: warning: Embedding is not possible. GRUB can only be installed in this setup by using blocklists. However, blocklists are UNRELIABLE and their use is discouraged..
/usr/sbin/grub-bios-setup: error: will not proceed with blocklists

Ah, now we learn something new again about your machine. Your disk uses Logical Disk Manager. I am not familiar with LDM, so I looked around a bit. I am sorry to say that it seems GRUB does not support it.

Since you can boot into the Windows, I suggest you add an entry for Ubuntu in the Windows boot loader itself. Check this out:
http://linuxbsdos.com/2012/07/21/how...ows-boot-menu/

"Please use EasyBCD with care, it’s a powerful tool that you can either make your life a lot easier or make it rather miserable by letting you shoot yourself in the foot." this quote i found on the link. pl. suggest or is there any other solution?

Of course, powerful software gives you access to the deep roots of the system, so a small mistake can render your system unusable. I understand you don't want to take the risk. Ok, check this out: https://bugs.launchpad.net/ubuntu/+s...2/+bug/1061255. I think workaround 3 should be helpful to you.

ou installed Ubuntu on the former Drive D: in Windows. So, it is used by Ubuntu and now has a EXT4 filesystem. As Windows can't show ext4 partition, you can't see that drive.

You can still see that drive by going to the "Disk management" in Windows. That partition should have label "unknown".

To run Disk management, press Start menu and type diskmgmt.msc and Press and hold Shift key and then hit Enter.

Ethan Stark