Grub rescue on boot up?

[boy18nj]

what happened-

i cloned my ubuntu partition to new ext4 partition using dd command. deleted the old partition. rebooted laptop, then i have error grub rescue.

obviously i searched on net on grub rescue, tried everything out there, still it didn't fixed the issue. it seems it's really bad. tried boot repair tool. still it didn't helped.

i've spent almost 2 days to fix this. but can't.

Although boot repair says repaired successfully, it's not. see the pastbin output-

http://paste.ubuntu.com/1618128/

[ahallubuntu]

~

[boy18nj]

thanks for replying.

yes the copied partition shows up data.

ubuntu@ubuntu:~$ sudo blkid
/dev/loop0: TYPE="squashfs"
/dev/sda1: LABEL="TOSHIBA SYSTEM VOLUME" UUID="3E345FA1345F5ACB" TYPE="ntfs"
/dev/sda2: UUID="7e759d52-ef42-4aa2-8b36-74c5584f482f" TYPE="ext4"
/dev/sda4: LABEL="30-1" UUID="a87fa281-7168-4c29-95b1-de30489fbaeb" TYPE="ext4"
/dev/sdb1: LABEL="PENDRIVE" UUID="1813-3B06" TYPE="vfat"
/dev/sdc1: LABEL="BOOT" UUID="F2FF-0501" TYPE="vfat"


ubuntu@ubuntu:~$ more /etc/fstab
overlayfs / overlayfs rw 0 0
tmpfs /tmp tmpfs nosuid,nodev 0 0
ubuntu@ubuntu:~$

where should i update UUID in /etc/fstab?

[oldfred]

You probably will have to use the chroot method to reinstall grub. As you have no grub in MBR, you have a grub in the sda2 partition boot sector that is looking for core.img in sda5 which you do even have a sda5. And you are missing grub.cfg.

I would suggest once chrooted you do the full uninstall and reinstall of grub2. Boot-Repair has advanced options that help you chroot and do a full reinstall of grub.

OR:
chroot & grub uninstall & reinstall -drs305
http://ubuntuforums.org/showthread.php?t=1581099

[ahallubuntu]

~

[boy18nj]

no it's not WUBI install.

[boy18nj]

You probably will have to use the chroot method to reinstall grub. As you have no grub in MBR, you have a grub in the sda2 partition boot sector that is looking for core.img in sda5 which you do even have a sda5. And you are missing grub.cfg.

I would suggest once chrooted you do the full uninstall and reinstall of grub2. Boot-Repair has advanced options that help you chroot and do a full reinstall of grub.

OR:
chroot & grub uninstall & reinstall -drs305
http://ubuntuforums.org/showthread.php?t=1581099


which one should i go with?

A. Only If You Have a Separate /boot partition. If you have a separate /boot partition run these commands. Most users do not have a separate /boot partition and should go to the normal partition section.

C. If You Have a Normal Installation. No separate /boot partition, not a Windows/Wubi installation.

[boy18nj]

i went ahead with C option (C. If You Have a Normal Installation. No separate /boot partition, not a Windows/Wubi installation.  ).

Now getting this error (in my previous attempts too, got this error but was never able o resolve it)-

ubuntu@ubuntu:~$ sudo chroot /mnt/temp
chroot: failed to run command `/bin/bash': No such file or directory

when i ran this command, it is successful

ubuntu@ubuntu:~$ /bin/bash
ubuntu@ubuntu:~$


Also tried-
sudo cp -r /bin /lib /mnt/temp this also, didn't fixed the issue.

Any idea, so why above error?

[boy18nj]

I'm stuck here-

root@ubuntu:~# chroot /mnt/temp
chroot: failed to run command `/bin/bash': No such file or directory
root@ubuntu:~# ldd /bin/bash
linux-vdso.so.1 => (0x00007fffe01cb000)
libtinfo.so.5 => /lib/x86_64-linux-gnu/libtinfo.so.5 (0x00007fe63f5a3000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fe63f39f000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fe63efe1000)
/lib64/ld-linux-x86-64.so.2 (0x00007fe63f7dc000)
root@ubuntu:~#

Any help is appreciated?

[oldfred]

Did you run the first commands to create a mount point and mount it?


sudo mkdir /mnt/temp
sudo mount /dev/sdXY /mnt/temp # Example: sudo mount /dev/sda5 /mnt/temp
Then run the chroot all one line:



for i in /dev /dev/pts /proc /sys; do sudo mount -B $i /mnt/temp$i; done
sudo cp /etc/resolv.conf /mnt/temp/etc/resolv.conf # May be required to connect to the Internet. sudo chroot /mnt/temp

[boy18nj]

Did you run the first commands to create a mount point and mount it?

Then run the chroot all one line:

yes, i did ran those all commands.

[boy18nj]

I'm getting sick of this. done everything.

[ahallubuntu]

~

[boy18nj]

there is a link that explains how to fix this- http://brucencnp.blogspot.com/2010/10/chroot-failed-to-run-command-binbash-no.html

but i don't get the required libraries.

[ahallubuntu]

~

[boy18nj]

Oh, now I understand: you need to mount the partition - say in /mnt/temp - then find the fstab there:


more /mnt/temp/etc/fstaband not the one from the live CD.

this seems to be correct, as you have expected.

root@ubuntu:/lib64# more /mnt/temp/etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc nodev,noexec,nosuid 0 0
# / was on /dev/sda5 during installation
UUID=7e759d52-ef42-4aa2-8b36-74c5584f482f / ext4 errors=remount
-ro 0 1
root@ubuntu:/lib64#

[boy18nj]

Can you give the output of:


ls /mnt/temp?

root@ubuntu:~# ls /mnt/temp
bin home media srv vmlinuz
boot initrd.img proc sys vmlinuz.old
C:\nppdf32Log\debuglog.txt initrd.img.old run tmp
dev lib sbin usr
etc lost+found selinux var
root@ubuntu:~#

[boy18nj]

i never imagined, i would be stuck.

should i now go ahead with fresh ubuntu installation?

[ahallubuntu]

OK, the directory looks OK.

It looks like the chroot worked? You have a root prompt. Or did you login as root to get there?

If you did the chroot successfully, then do the grub-install and update-grub commands within the chroot environment.

But you'll have to look at the UUID thing I mentioned before and /mnt/temp/etc/fstab . Look for the line that has just "/" in it. The UUID must match the UUID of the new partition. Otherwise, it's not going to boot even after you've fixed Grub.

[boy18nj]

i never imagined, i would be stuck.

should i now go ahead with fresh ubuntu installation?

I installed fresh ubuntu in 20 minutes after taking backup's.

Am happy.

Earlier wasted 2 days in GRUB ubuntu issue.

[boy18nj]

Now I'm going to create such a setup where i keep my all files in separate partition.

And Ubuntu installed in separate partition. Will create an image of it. Whenever something happens just restore the image.

This approach is little different from traditional slow changing data backup's.

[oldfred]

I know an image gets obsolete quickly. So I just plan on a new install. So then I backup the things that may change. Mostly /home which I keep in my / (root) and my data which is in separate data partitions.

I prefer a separate /data partition. Then you can easily share your data without having the conflict of the user settings in hidden files & folders. Works best if all installed systems are Debian based, see UID issues below.

The actual user settings are small. My /home is 2GB with most of that as .wine with Picasa which I have not yet moved to my /data. Because /home is small I now keep it as part of / (root).
Then I can have a fully functioning system on one drive but have data linked in from other partitions on other drives.

Data can be shared without the possible conflicts of user settings being different in different versions. I only copy some settings from one install to the next, normally. But I have to separately back up /home and the /data partition. Also saves the error of reformating a /home partition accidentally. I never reformat my /data and just configure / for install.

Splitting home directory discussion and details:
http://ubuntuforums.org/showthread.php?t=1811198
http://ubuntuforums.org/showthread.php?t=1901437
http://ubuntuforums.org/showthread.php?t=1734233&highlight=%2Fdata
Link is on move home but see post by bodhi.zazen on data partition #6
http://ubuntuforums.org/showthread.php?t=325048

Opposing viewpoint on separate data partitions - post 14 srs5694:
http://ubuntuforums.org/showthread.php?t=1738065
Shared Data with Different operating systems, different uid and gid issues - Morbius1
http://ubuntuforums.org/showthread.php?t=1675381


Oldfred's list of stuff to backup May 2011:
http://ubuntuforums.org/showthread.php?t=1748541