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For a few years I have been using Wubi to install Ubuntu on my machine. I have two HDs on it. Windows resides on the first drive, and I've put Ubuntu on the second one. However a recent update to grub (that's my best guess) makes Ubuntu unbootable. I can reproduce the following by: + installing the latest 10.04 (since they updated it a few days ago) + installing 11.04 + installing 10.10 and then, from within the system, install all updates provided

Let me describe the 10.10 route: I install the system, default settings, and booting in it works just find. Here is the relevant information from grub.cfg:

### BEGIN /etc/grub.d/10_linux ###
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/10_lupin ###
menuentry "Ubuntu, Linux 2.6.35-22-generic" {
insmod part_msdos
insmod ntfs
set root='(hd1,msdos3)'
search --no-floppy --fs-uuid --set 46b2c65db2c650db
loopback loop0 /ubuntu/disks/root.disk
set root=(loop0)
linux /boot/vmlinuz-2.6.35-22-generic root=/dev/sdb3 loop=/ubuntu/disks/root.disk ro   quiet splash
initrd /boot/initrd.img-2.6.35-22-generic
}
...
### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Windows 7 (loader) (on /dev/sda2)" {
insmod part_msdos
insmod ntfs
set root='(hd0,msdos2)'
search --no-floppy --fs-uuid --set b296c2ae96c27281
chainloader +1
}
### END /etc/grub.d/30_os-prober ###

The grub version installed with 10.10 is 1.98+20100804-5ubuntu2

After updating the system (not to 11.04, but installing all updates recommended when running the update management tool for the first time), grub's version is not 1.98+20100804-5ubuntu3.3. grub.cfg looks similar to before, apart from the new kernel version and entries. It does add some code early in the file:

...
insmod part_msdos
insmod ntfs
set root='(hd1,msdos3)'
search --no-floppy --fs-uuid --set 46B2C65DB2C650DB
loopback loop0 /ubuntu/disks/root.disk
set root=(loop0)
....

and here's the new Ubuntu entry:

menuentry "Ubuntu, Linux 2.6.35-30-generic" {
insmod part_msdos
insmod ntfs
set root='(hd1,msdos3)'
search --no-floppy --fs-uuid --set 46B2C65DB2C650DB
loopback loop0 /ubuntu/disks/root.disk
set root=(loop0)
linux /boot/vmlinuz-2.6.35-30-generic root=UUID=46B2C65DB2C650DB loop=/ubuntu/disks/root.disk ro   quiet splash
initrd /boot/initrd.img-2.6.35-30-generic
}

Upon boot, however, I get the dreaded "ALERT! /host/ubuntu/disks/root.disk does ont exist. Dropping to a shell! Running "ls" at this shell reveals that /host points to my first drive, maybe it should be the second one.

At first it sounded like the bug from https://bugs.launchpad.net/ubuntu/lucid/+source/grub2/+bug/742967, but since the page claims that 1.98+20100804-5ubuntu3.3 fixes this bug, maybe it has not been fixed for me (or there is another reason for the error).

Any ideas or suggestions?

share|improve this question
    
Installing 10.04, then 11.04 and then 10.10 are independent actions - a complete uninstall is required before each new install. The change to grub is using the UUID to identify the partition instead of the partition /dev/sdb3. The "search --no-floppy..." line does exactly the same. So this shouldn't be the problem. Does the root.disk exist? what's the UUID on /dev/sdb3 i.e. what's the output of "sudo blkid"? –  bcbc Aug 4 '11 at 16:01
    
just to clarify: I always wiped the drive before starting one of the wubi installs. I'll check sudo blkid. –  user22787 Aug 5 '11 at 10:49
    
aah! The two partitions have the same UUIDs - Windows volumne numbers are just too short :( I'll try changing the UUID of /dev/sdb3 and report back. –  user22787 Aug 5 '11 at 10:58
    
Ah, that will do it! PS Wubi doesn't need a separate drive, and you don't need to manually do anything to uninstall - reinstalling will automatically uninstall the old version, or you can go to Control Panel, Add/remove and double click "Ubuntu" to remove. –  bcbc Aug 5 '11 at 13:19
    
changing the UUID did the trick. Thanks! –  user22787 Aug 7 '11 at 20:18
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1 Answer 1

The two partitions have the same UUIDs - Windows volumne numbers are just too short :( I'll try changing the UUID of /dev/sdb3 and report back. – user22787 Aug 5 '11 at 10:58

changing the UUID did the trick. Thanks! – user22787 Aug 7 '11 at 20:18

Comments valued and question answered by OP

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