Re: [orca-list] problems booting into linux from an external hard drive

[Michael Whapples <mwhapples aim com>]

Hello,
Before I start, I will say now, I am more experienced with lilo as a
boot loader than grub (which I believe is the ubuntu default), but I
feel some of the ideas will be useful, if it only helps you understand
documentation, although I would hope it might be a bit more useful.

Firstly I would ask whether you can see anything, or if you can get
someone who can to check something. When your computer boots, is there a
new screen (with a boot menu) shown early in the boot process? It is
likely also to take your computer longer to boot if there is as it will
wait for some time at this screen. If there is, then you need to select
the linux option (it may be called ubuntu or something similar, I am not
sure what ubuntu labels itself as). If you will need a beep when it gets
to this, then you might be able to do this by inserting a "system bell
character" in the boot message in the grub configuration file (this is
where I am limited as it won't be the same file as lilo uses).

If no boot screen is shown, then you may need to access the systems bios
to set it to boot from a USB device before the internal device. If this
is possible then if you unplug the USB drive and boot it should boot
windows. Please refer to system documentation about bios access and
whether it supports booting from USB. Should this not be an option, or
you would prefer not to access the bios, read on for my next option.

It is possible for lilo to be installed to a floppy disk, it probably is
possible to install grub to a floppy as well. Again if you aren't going
to change boot loader my specific help is limited here. In the past I
had set up a floppy with lilo so that if I wanted windows I left the
floppy out, and if I wanted linux I put the floppy in to boot. This
floppy needed the default OS set to linux and delay (prompt time) set to
0, so it would just go straight in to linux. You may find the next
suggestion useful to achieve the one just made. Should this not be
possible as well (due to floppy drives becoming obsolete, then read on
further.

Should you be reading this still looking for a solution, then your linux
system is probably not possible to access at the moment. Use something
like the ubuntu live CD and chroot into the USB drive system (eg. in a
command window use a command such as "chroot /USB-drive" assuming that
the USB drive is mounted at /USB-drive). Now modify the grub
configuration file to install grub to the internal disk of your computer
and run grub to make the change.

I would say, although installing linux on a USB drive may be good (so
that should you get in a mess with it, you can unplug the drive and the
system is probably back to what it was), it may not be the simplest as I
don't know how external drives get labelled (eg. if you install with no
other USB drive in the machine, will the drives be numbered the same
should you boot with another USB drive connected? If the numbering is
different then it might cause a problem).

Should you have further questions, please ask them, I may have missed
something by trying to keep this short.

From
Michael Whapples
On Mon, 2007-11-19 at 11:40 -0500, Beth Wright wrote:
> Hi.
>  
> I just installed Ubuntu 7.04 from the live CD onto an external USB
> 40-gig hard drive, which is plugged into my Windows XP desktop
> computer.  I think the installation went okay, but I don't know how to
> boot into this extra hard drive.  Is it possible to do this by
> inserting the live CD and issuing some commands?  For a while, I
> thought I'd erased my XP hard drive by mistake, because I had so much
> trouble getting back into Windows after the installation.  I chose the
> extra hard drive because someone on one of the lists said thas method
> was preferable to dual-booting if you wanted to install Linux on a
> Windows system.  Thanks in advance.
>  
> Beth Wright