Release notes should warn against installing Ubuntu on old machines

[Matt Zimmerman]

On Tue, Mar 06, 2007 at 10:12:15PM +0000, Sitsofe Wheeler wrote:
> Ubuntu can have serious problem when installed on machines whose BIOSes
> cannot read files past the 1023rd cylinder. This is a well known problem
> and there have been a fair few reports of this problem listed on the
> forums as well as within launchpad. One of the more recent version of
> these reports was marked as rejected:
> https://launchpad.net/ubuntu/+bug/88633 I feel this is wrong as there is
> no indication that Ubuntu is a poor fit for old machines. The installer
> should check to see if the BIOS is older than 2001 and if so, put up a
> warning saying that Ubuntu is not suitable for such an old system.
> Additionally, the release notes should also mention that Ubuntu is not
> designed for old systems to save people the negative experience of going
> all the way through the install and then being unable to boot the machine
> at the end. Perhaps a force option can be used at grub/isolinux for those
> who want to go ahead anyway...

There are a few reasons why this issue is complex.

Most GRUB failure modes only provide a numeric error code, and so it's
difficult to determine the cause of the issue.  You may see many similar
reports, but it isn't necessarily true that they're all caused by a
particular BIOS issue.  We know that there are situations where Ubuntu will
install to the hard drive and then fail to boot, but the range of causes and
solutions is not very well understood by the development team.

Your proposed solution, to draw an arbitrary cutoff point and discourage
users from using Ubuntu on systems over a certain age, would unnecessarily
exclude a large number of systems capable of running Ubuntu without a
problem.  I have personally run Ubuntu on several systems older than 2001,
and of various ages with hard drives with more than 1024 cylinders, and not
had a problem.

Whether the system can boot a default Ubuntu configuration depends on a
number of factors other than the number of cylinders on the disk, such as
whether the BIOS supports LBA mode.  Furthermore, the solutions to the
problem also vary.  Often, changing the BIOS configuration is sufficient.
Sometimes (such as when another installed operating system is relying on the
current BIOS configuration), this is not an option.

A much better step would be to develop a test which could detect whether the
system has this problem.  As a first step, this could be used in the
installer to warn the user of a potential problem before they take any
destructive steps.  Later, it may be possible to work around the problem
automatically by using a different partition layout, so that the kernel is
always near the beginning of the disk, in which case the earlier work to
detect it would continue to be useful.

We know that Ubuntu, in various flavours and configurations, *is* suitable
for older systems, so we should not exclude them out of hand.

I believe Paul Sladen knows a thing or two about PC BIOS quirks, so perhaps
he has some input for us.

-- 
 - mdz