Help! Grub2 problem

[ponder]

Ok, my PC froze, I waited & then hit the reset button.

Now on reboot I get:
error: unknown filesystem
grub rescue>

I did a repair on the FS and now get:
error: file not found
grub rescue>

The above is on Ubuntu 11.10 AMD64.

I only have the Alternate install CD. Can I chroot from this cd and reinstall grub?

Anyone got the steps for this by any chance as I'm on limited net access now...

 

[ponder]

I also have a Debian 6 based live USB available.

 

[ponder]

Found this http://opensource-sidh.blogspot.com/2011/05/install-grub-rescue-recovery-in-ubuntu.html

 

[froot]

I had a similar problem with Ubuntu (okay, mine was more related to EFI and Grub2 not liking one another).

I used Boot-Repair to sort out my Grub issues (normal grub console commands wouldn't work).

You'd do yourself a favour in the long run by writing this to CD, as you get a bootable version (similar to Hirens).

 

[ponder]

I had a similar problem with Ubuntu (okay, mine was more related to EFI and Grub2 not liking one another).

I used Boot-Repair to sort out my Grub issues (normal grub console commands wouldn't work).

You'd do yourself a favour in the long run by writing this to CD, as you get a bootable version (similar to Hirens).

Iḿ beginning to think my problems are way bigger than just grub, sigh! i followed this guide http://opensource-sidh.blogspot.com/...in-ubuntu.html but it wont even mount the filesystem.

I have been faffing around and iḿ livid right now, already destroyed on dvd writer tray in anger so, came pretty close to putting my fist through a lcd as well.

I fscking hate ext4, itś the second time it has borked itself in my experience. I should have learned my lesson after the first incident.

Think itś best I switch off everything right now before i start torching schit.

 

[froot]

Iḿ beginning to think my problems are way bigger than just grub, sigh! i followed this guide http://opensource-sidh.blogspot.com/...in-ubuntu.html but it wont even mount the filesystem.

I have been faffing around and iḿ livid right now, already destroyed on dvd writer tray in anger so, came pretty close to putting my fist through a lcd as well.

I fscking hate ext4, itś the second time it has borked itself in my experience. I should have learned my lesson after the first incident.

Think itś best I switch off everything right now before i start torching schit.

That link, sir, does not work

(The original one does, so just busting your balls. I should try that one day)

 

[MyWorld]

Just make sure the file system is intact or that you can at least access it, run a LiveCD and see if you can get access the file system.

From here on out you can repair the file system (http://linuxexpresso.wordpress.com/2010/03/31/repair-a-broken-ext4-superblock-in-ubuntu/) should it be needed and or recreate /boot and or re-install Grub.

In my experience this usually points to a drive that is busy dying, not spinning down correctly, etc, etc and eventually the file system gets corrupted. If the drive is on the older side, you might want to replace it ASAP before you loose all your data.

 

[ponder]

Gparted reports the partition as ext2 instead of ext4. I can read the /home ext4 partition & win7 NTFS partitions on the drive just fine. diagnostics indicate the drive is fine. Somehow the FS went for a ball of snot on the / partition. I'm gonna watch some mind numbing tv now, this will have to be sorted out tomorrow.

Just make sure the file system is intact or that you can at least access it, run a LiveCD and see if you can get access the file system.

From here on out you can repair the file system (http://linuxexpresso.wordpress.com/2010/03/31/repair-a-broken-ext4-superblock-in-ubuntu/) should it be needed and or recreate /boot and or re-install Grub.

In my experience this usually points to a drive that is busy dying, not spinning down correctly, etc, etc and eventually the file system gets corrupted. If the drive is on the older side, you might want to replace it ASAP before you loose all your data.

 

[BigAl-sa]

Just as a matter of interest, what drive and m/b is it you're having trouble with? I built a PC for a friend which had similarish troubles recently. A simple fsck sorted it out, but I also had to move the hdd up the boot order in the BIOS.

 

[ponder]

Just as a matter of interest, what drive and m/b is it you're having trouble with? I built a PC for a friend which had similarish troubles recently. A simple fsck sorted it out, but I also had to move the hdd up the boot order in the BIOS.

250GB Seagate 7200.11 HDD & Gigabyte GA-EG31M-S2 MB. This is not the problem though as I've been running this setup for years. I found the cause of the failure though, see below.

Somehow the FS went for a ball of snot on the / partition.

Trying to use the PC again resulted in it coming on, going off & coming on again & stay on or on other power on attemps I get continues short beeps which the MB manual say is a power related issue. So I suspected the 4+ yr old Gigabyte PSU which I purchased in haste when my Antec died (could not wait for mail order), actually amazed it gave me that long service. I swapped the gigabyte for another PSU with a higher rating (or so the label says) I had lying around (ying yang brand) and PC starts up fine.

I suspect when the PC froze the PSU probably did somehting funny and hence the corruption of the FS which I now need to fix.

I'm gonna install Ubuntu on a spare 2.5" drive and use that to try and fix the FS.

 

[bin3]

Something to have a look at as well:

Depending on your kernel version and options, it might be that your current kernel doesn't have support for all the ext2-4 types enabled. This sometimes happens with oldish systems being upgraded to pretty recent ones.

Make sure your kernel supports all ext2/ext3/ext4 file types. I prefer to compile them into the kernel, not as a module.

Download and use Knoppix http://knoppix.net/ to test if your installation is still ok

 

[ponder]

Something to have a look at as well:

Depending on your kernel version and options, it might be that your current kernel doesn't have support for all the ext2-4 types enabled. This sometimes happens with oldish systems being upgraded to pretty recent ones.

Make sure your kernel supports all ext2/ext3/ext4 file types. I prefer to compile them into the kernel, not as a module.

Download and use Knoppix http://knoppix.net/ to test if your installation is still ok

Yes, this is why I'll be installing the exact same os on a different drive, upgrade the kernel modules and then try and fix my existing install from there. I already have the iso so will save time on downloading & bandwidth.

If I can get my apt cache of the existing drive I won't even be phased about reinstalling the OS.

 

[ponder]

From here on out you can repair the file system (http://linuxexpresso.wordpress.com/2010/03/31/repair-a-broken-ext4-superblock-in-ubuntu/) should it be needed and or recreate /boot and or re-install Grub.

Well I tried the above link and after holding in 'y' for a very long time to go thourgh a lot of inode issues I now have a mountable FS but I see nothing on it except for 'lost+found' folder....

 

[ponder]

Well I gave up on my root partition after I recovered a whole lot of .deb files which I assume was from my /var/cache/apt folder but most were corrupted.

So I backed up my /home, formatted / & /home and did a command line (base) install of Ubuntu 11.10 again. Fortunately for me somewhere in my infinite wisdom I made a backup of my /var/cache/apt folder so reinstalling stuff is easy and fast after I restored the contents. Just need to remember to rsync this folder so it's more up to date for future use.

Unlike the previous time where I installed Xubuntu-desktop meta package this time I just installed a barebones xfce4. Well the difference is night and day wrt boot time & responsiveness. Dunno why they can't leave good enough alone and try making it like gnome which it's not.

Well after using a temp install of ubuntu I'm glad it's over as unity was driving me nuts and the fonts were making my eyes bleed.

Anyway, I'm a happy camper now, just need to find some super glue to fix the optical burner tray I broke