T. Tofus von Blisstein wrote:
Hello,
I have linux and openbsd installed on a single drive. Linuxy fdisk shows
Device Boot Start End Blocks Id System
/dev/sda1 1 24017 192916521 5 Extended
Partition 1 does not end on cylinder boundary.
/dev/sda2 * 24018 30401 51279480 a6 OpenBSD
OpenBSD is in an extended partition...don't know that this works in all
(or any) cases, and the fact that it doesn't work in yours doesn't
surprise me.
Even if all the OpenBSD bits work to boot off extended partitions, they
would have to be installed properly...and that would be easier done
wrong than right, I think.
/dev/sda5 1 127 1020064+ 83 Linux
/dev/sda6 2708 23506 167067936 83 Linux
/dev/sda7 128 2707 20723818+ 83 Linux
/dev/sda8 23507 24017 4104576 82 Linux swap / Solaris
The linuxy menu.lst shows
title OpenBSD
rootnoverify (hd0,1)
savedefault
makeactive
chainloader +1
After a clean install, the openbsd installer says: "installboot: broken MBR"
which may also be an issue with OpenBSD in an extended partition (or
improperly set up extended partition, which is entirely believable,
since you didn't think it important to indicate how you set it up).
Then GRUB protests when booting openbsd with error 13: "Invalid or
unsupported executable format"
which appears to mean you have tried to have grub try to load the
OpenBSD kernel. This has not worked for a very long time. I think I
heard something about the grub people have very recently reved their
code to actually successfully load some modern version of OpenBSD's
kernel, but I doubt it has made it into most main-stream distros, nor
would I recommend it if it did.
I have seen the "does not end on cylinder boundary." warning of fdisk
a number of times in the past, and yet I was able to boot in openbsd.
I think it must be a linux bogus.
cylinder boundaries are an old hacker's tale. They don't matter in real
life (at least with any modern OS I've worked with). It fascinates me
that they obsess over non-issues like that which never seem to cause
real problems, then encourage you to try to boot from extended
partitions without the slightest warning, which DOES cause real problems.
You may be able to properly configure an extended partition so that it
would be bootable for OpenBSD (hint: more than one MBR), but I'm not
sure all BIOSs would successfully walk the MBR chain, so if your MoBo
died and you replaced it (or an upgraded BIOS has a bug), your disk may
become unbootable. I'd highly recommend keeping OpenBSD in a primary
partition.
Nick.
