Hard drive confusion

English Install/Boot/Login
1

Could somebody explain why this happened to me and possibly how to correct it?

I have a SATA drive in my box that I installed Suse on (10.3). Call it “drive A”. It functions as expected. I wanted to try out the newest Ubuntu. So as not to damage Suse I installed a separate IDE drive. Call it “drive B”.

I then set the BIOS so that drive A was disabled and drive B was enabled and made it the only drive to boot from. I booted from the Ubuntu CD and installed it on drive B. It did not ask me if I wanted to install grub in the MBR or on the Ubuntu partition.

When I tried to boot drive B (the only enabled drive) it would not boot telling me that there was no OS on it. After panicking I reset the BIOS so that only drive A was active. I booted and was presented with a GRUB menu from which I could choose either Ubuntu or Suse. Both were bootable.

I decided to try and correct the problem by copying the old drive A MBR which I had backed up (using “dd”) back onto Drive A. Nothing changed. I still can’t boot drive B and still get the Ubuntu generated grub menu when I boot drive A.

2

Boot up and get the output from a su terminal:

fdisk -l

FYI. If you want to disable a drive, just pull the power out from it. (With the box already shut down of course!)
But that should not be necessary anyway, if you understand boot ordering in BIOS and understand the info you are presented with at install. Personally I don’t like the Ub* installer - it assumes you are stupid.

Partitioning/Install Guide - openSUSE Forums
Ignore any windows info, just get the principles in mind.

3

FROM A SUSE BOOT

fdisk -l

Disk /dev/sda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x000cd494

Device Boot Start End Blocks Id System
/dev/sda1 1 2433 19543041 7 HPFS/NTFS
/dev/sda2 * 2434 5044 20972857+ 83 Linux
/dev/sda3 5045 9729 37632262+ 83 Linux

Disk /dev/sdb: 320.0 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xffce0322

Device Boot Start End Blocks Id System
/dev/sdb1 1 3648 29302528+ 7 HPFS/NTFS
/dev/sdb2 3649 3892 1959930 82 Linux swap / Solaris
/dev/sdb3 3893 7540 29302560 83 Linux
/dev/sdb4 7541 38913 252003622+ f W95 Ext’d (LBA)
/dev/sdb5 * 7541 10151 20972826 83 Linux
/dev/sdb6 10152 11235 8707198+ 83 Linux
/dev/sdb7 11236 38913 222323503+ 83 Linux

FROM AN UBUNTU BOOT

:~$ sudo fdisk -l

Disk /dev/sda: 320.0 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xffce0322

Device Boot Start End Blocks Id System
/dev/sda1 1 3648 29302528+ 7 HPFS/NTFS
/dev/sda2 3649 3892 1959930 82 Linux swap / Solaris
/dev/sda3 3893 7540 29302560 83 Linux
/dev/sda4 7541 38913 252003622+ f W95 Ext’d (LBA)
/dev/sda5 * 7541 10151 20972826 83 Linux
/dev/sda6 10152 11235 8707198+ 83 Linux
/dev/sda7 11236 38913 222323503+ 83 Linux

Disk /dev/sdb: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x000cd494

Device Boot Start End Blocks Id System
/dev/sdb1 1 2433 19543041 7 HPFS/NTFS
/dev/sdb2 * 2434 5044 20972857+ 83 Linux
/dev/sdb3 5045 9729 37632262+ 83 Linux

I’ve done that in the past, but this box is particularly small, crowded, and inclined to cutting fingers on sharp edges.

I agree. But in this case it might have been correct in the evaluation of the user, me.

I read the guide, but did not learn anything pertinent to my problem. Perhaps a better question would be, is there a utility that examines the MBR and tells me what partition it is trying to boot? I try to avoid using the MBR method. Perhaps Ubuntu confused the physical drive order method hd(x,x) with the assigned order that the drives boot. I’ve run into that with some BIOSes. Or possibly it was confused because one is IDE and the other SATA. Either way I find it a fascinating problem.

4

OK. So you can see how one OS is calling a HD sda and the other OS sees it as sdb.

The fact that one HD is sata and the other IDE is fine I have this on my box. It’s really easy. Make sure the IDE is set to Master on the jumper.

It’s really just a matter of getting the HD’s in the right order in BIOS, making sure you know how the OS is seeing them.