I've been working on getting a couple of legacy OSes working in harmony with Linux on my main home PC. I've also been using Fedora Core 3, which uses the 2.6 kernel. This has lead to my discovery that the whole partition table thing has gotten even worse. Maybe everybody else knows this and I just didn't get the memo, but if not, the following may prove useful to others. Share and enjoy!
Definition: A "legacy OS", in this discussion, is a brain-damaged OS that does not provide any clue as to why it does things they way it does them, nor does it provide a way for you to fix it. Legacy OSes include the latest stuff from a certain large software company currently headquartered in the North-West USA. Background: Certain legacy OSes seem to think that hard disks should have a multi-dimensional geometry, rather then a simple linear geometry. This is called the "CHS geometry" (cylinder, head, sector). Modern OSes like Linux thankfully do not need this garbage, but some of us, myself included, are using legacy OSes, too. Since any hard disk made within the past 15 or so years doesn't use CHS, the BIOS invents one to make legacy OSes happy. If one only used a single OS, then this did not matter. When you combine a modern OS like Linux (which does not use CHS) and a legacy OS which uses CHS, however, you have to make sure everybody agrees as to what the invented geometry is. In this past, the Linux kernel provided some mechanisms for this. They were not perfect, but they worked most of the time. New trouble: With Linux 2.6, certain powers decided that legacy OSes were Somebody Else's Problem, and the CHS support in the kernel was changed and reduced. This has led to major lossage when dealing with legacy OSes. Programs (like parted) which previously depended on the kernel to provide good answers got hosed. This could easily render a legacy OS unbootable. Fixes include paying attention to the order of operations, using certain partitioning tools for certain tasks, and/or fixing up partition table geometry entries manually. It is apparent that not everyone agrees on the issues at hand. Things are likely to continue to change and evolve. References: A thread on bug-parted about the impact of the kernel changes http://lists.gnu.org/archive/html/bug-parted/2004-12/msg00022.html A thread on LKML about changes in kernel support for disk geometry http://tinyurl.com/6elmz A message that explains how to prevent and/or fix geometry corruption http://www.redhat.com/archives/fedora-devel-list/2004-May/msg00908.html Large Disk HOWTO http://www.win.tue.nl/~aeb/linux/Large-Disk.html -- Ben Scott <[EMAIL PROTECTED]> | The opinions expressed in this message are those of the author and do | | not represent the views or policy of any other person or organization. | | All information is provided without warranty of any kind. | _______________________________________________ gnhlug-discuss mailing list [email protected] http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss
