Another disk image attempt failed :(

[Gary W. Swearingen]

Daniel Carrera <daniel.carrera at zmsl.com> writes:

> Hello,
>
> I tried something else to effectively make a "disk image" of an Ubuntu OEM installation, but that didn't work
> either. This is what I did:
>
> Note: /dev/hda is the working installation and /dev/hdb is where I want to put the clone.
>
> 1. Boot from a rescue disk.
> 2. dd if=/dev/hda of=/dev/hdb count=1 bs=446
>    This should copy the bootloader part of the MBR without touching the
>    partition part.

Sure wish you'd say what bootloader you're using.

> 3. fdisk to create the appropriate partitions that the Ubuntu OEM
>    expects (hdb1 - ext3, hdb2 - extended, hdb5 - swap).

I wonder why hdb2 isn't swap, but it hardly matters.  And some say the
swap should be on the fastest part of the disk, but I never can
remember if that's the beginning or end.  (With modern disks, there
are several other places just as good, but one doesn't know where.)

> After this, I still can't boot from hdb (after pulling out hda). It says "DISK BOOT FAILURE. INSERT SYSTEM DISK AND
> PRESS ENTER".
>
> So... the MBR bit didn't work. I don't know what else to try (btw, yes, hdb1 has the bootable flag set, but it shouldn't
> matter if the problem is right at the MBR).

(FYI, if it was an IBM-DOS-type MBR with no such flag set, you'll get
some kind of error; maybe that one.  But, AFAIK, only the IBM-DOS-type
MBR reads that bit, and you probably don't have that.)

That message sure looks like it's from the BIOS.  I supposed there's
and outside chance that, with your sneaky scheme there, you've never
got the last two "magic bytes" of the MBR set, and the BIOS won't like
that.