Dual OS boot up problem

[tagengo]

Hi all, I have a problem with my Acer Aspire 721 and hoping someone would be able to help.
This isn't EXACTLY a kubuntu issue, although I wonder if anyone with a similar set up has had a similar problem.

The system has been partitioned and running dual boot windows 7 and Kubuntu Natty without a problem for the last month.
Last night I ran a system update which caused windows 7 to crash on boot up from then on. : I have run the Acer eRecovery to revert windows to factory defaults.

Now when I try to run windows I get:
error: no such device : B408884908880D14
error: no such disk.

Kubuntu still runs perfectly fine, I can even access the windows partition while in kubuntu and see that the files all seem to be there.
I guess it has something to do with the GRUB? However, I'm certainly not the most tech-savvy, so if anyone can suggest anything to try I would be really grateful.

Thanks

[oshunluvr]

Re: Dual OS boot up problem

I'm amazed that the Acer recovery didn't wipe grub altogether. I would assume that the recovery changed the UUID of the windows partition except that number is half as long as a UUID would be.

Open a terminal and type sudo blkid and post the out put, then make a copy of your /boot/grub/grub.cfg file and attach it to your reply. I think you'll have to rename it .txt to attach it (Attaching is an option under Additional Options, just below and left of the posting window).

If you're sure enough of your own skills, compare the UUID's in grub.cfg to the output of blkid and see if there are any "strangers" in grub.cfg.

Likely, running sudo update-grub would fix any UUID changes, if that is in fact what's wrong.

[tagengo]

Re: Dual OS boot up problem

AHA!

I ran the grub update and it seems to have sorted the problem out.

Such a simple solution it feels almost embarrassing , but thank you so much for your help!

[oshunluvr]

Re: Dual OS boot up problem

Great! I love the easy ones... 8)

[tagengo]

Re: Dual OS boot up problem

I spoke too soon!

I ran windows and all seemed fine. Restarted the system and now it won't boot from the HD, the computer just restarts after a couple of seconds.
I can run kubuntu from the live usb still and can access file on the HD.

Reinstalled and updated grub (windows did remove it in the end) but doesn't seem to have any effect.

Can anyone suggest anything to remedy this?

[bsniadajewski]

Re: Dual OS boot up problem

Could a guy just change the UUID pointers in fstab to straight /dev/sd** notation?

[oshunluvr]

Re: Dual OS boot up problem

Could a guy just change the UUID pointers in fstab to straight /dev/sd** notation?

Yes.

As far as the OP: When you say it won't boot from the hard drive - you mean grub doesn't work or you can't boot an OS?

[tagengo]

Re: Dual OS boot up problem

After displaying the ACER screen for a couple of seconds, the screen goes blank and the system restarts (unless I have the live USB connected, in which case it loads from that).

I'm not sure if that means there is an issue with the grub, or something else.

Could a guy just change the UUID pointers in fstab to straight /dev/sd** notation?

Not really sure what this means?

[oshunluvr]

Re: Dual OS boot up problem

Could a guy just change the UUID pointers in fstab to straight /dev/sd** notation?

Not really sure what this means?

He means replacing "UUID=..." in /etc/fstab with "/dev/sda2" - the older way of doing it. For the record, you can also mount using labels or ID's.

As far as the ACER, boot to the USB, mount your Kubuntu partition somewhere (I'll use /mnt for my example) and try:

sudo grub-install --root-directory=/mnt /dev/sda

and try again (unless you get an error).

[bsniadajewski]

Re: Dual OS boot up problem

Could a guy just change the UUID pointers in fstab to straight /dev/sd** notation?

Not really sure what this means?

He means replacing "UUID=..." in /etc/fstab with "/dev/sda2" - the older way of doing it. For the record, you can also mount using labels or ID's.

Right. I had a similar problem where the OS couldn't find a particular partition. I saw that the UUID's didn't match up, so I just changed "UUID=***" to /dev/* and everything work well.

[vinnywright]

Re: Dual OS boot up problem

Could a guy just change the UUID pointers in fstab to straight /dev/sd** notation?

Not really sure what this means?

He means replacing "UUID=..." in /etc/fstab with "/dev/sda2" - the older way of doing it. For the record, you can also mount using labels or ID's.

Right. I had a similar problem where the OS couldn't find a particular partition. I saw that the UUID's didn't match up, so I just changed "UUID=***" to /dev/* and everything work well.

and or run

sudo blkid

and get the corect UUID

VINNY

[oshunluvr]

Re: Dual OS boot up problem

I read some (grub or kernel) documentation somewhere that using UUID's is of little or no value in a single machine environment.

I use because it is the default, but you can change your system back to the "old" way.

I think if you are a distro-hopper that installs to a partition often that having to edit all your fstab's would be tiresome.

[tagengo]

Re: Dual OS boot up problem

Could a guy just change the UUID pointers in fstab to straight /dev/sd** notation?

Not really sure what this means?

He means replacing "UUID=..." in /etc/fstab with "/dev/sda2" - the older way of doing it. For the record, you can also mount using labels or ID's.

As far as the ACER, boot to the USB, mount your Kubuntu partition somewhere (I'll use /mnt for my example) and try:

sudo grub-install --root-directory=/mnt /dev/sda

and try again (unless you get an error).

I've done this now, instead of restarting itself it now comes to a screen

[ mininal BASH-like line editing is supported. For the first word, TAB lists possible command completions. Anywhere else TAB lists the possible completions of a device/filename. ]

grub>

I tried command 'boot' and got message Error 8: Kernel must be loaded before booting

I also tried to manual amend the fstab file, the UUIDs were wrong, but kept getting denied access to save it

I guess I'm doing something wrong still

[tagengo]

Re: Dual OS boot up problem

Could anyone suggest what has gone wrong?

Thanks

[vinnywright]

Re: Dual OS boot up problem

fire up the Kubuntu live cd/USB and post the outputs of these commands ran in a terminal.

sudo fdisk -l

and

sudo blkid

if you can get into the Kubuntu install with dolphin post the contents of

/boot/grub/grub.cfg

it sounds like you have been successful at reinstalling grub to the MBR of the primary drive but grub cant find it's setup files (grub.cfg)

hears a good read on the subject of grub https://help.ubuntu.com/community/Gr...alling%20GRUB2

especially the section...." Troubleshooting Preparation "

VINNY