[sf-lug] Multiboot

[Akkana Peck]

Rick Moen writes:
> > Multiboot is an accident waiting to happen except in the hands of
> > (rare) methodical people who take great care to not step on its inherent

Michael Paoli writes:
> Yup, it's relatively fragile, and typically requires very careful
> handling to not seriously break it.

Yes, you're both right, of course.

It's sad. It was so easy in the grub 1 days; if you made a separate
/boot partition, all the info on distros lived there, and multiple
distros all shared it happily because the syntax didn't change.

Grub 2 broke that model and insisted that one distro be the "master
distro" that owns boot, with all the configuration files stored all
over the root filesystem instead of in /boot. You're right, managing
this in grub2 is probably not for the faint of heart, and aaronco36
gave an excellent list of the important issues.

aaronco36 writes:
> OTOH, multiboot *can* be and probably *is* the way to go for persons with
> more multiboot experience should such persons not have the RAM+CPU hardware
> resources on their older computers to run virtual machines.
> 
> An intended side benefit is that having a second or third bootable distro
> allows one to use a backdoor means of getting into one's system w/o using
> live media should one installed distro somehow fail to boot up.

Yes. I always have multiple boot partitions on my machines, not for
frequent distro-hopping nor for other OSes like Windows, but for
upgrades. When the time comes to upgrade to a new distro release, I
cp -ax the current root filesystem to a spare partition, edit fstab,
MAKEDEV in /dev (this part might not be needed any more), and boot
into the copy. Then I upgrade the copy, knowing that my working
distro is safe.

This backup is sometimes invaluable. Like the morning last year when
I booted to find X didn't run. I was on a deadline and didn't have
time to spend half the day trying to chase down a system bug.
Fortunately I had a partition with an older Debian that hadn't been
updated in a while, so I was able to boot off that to get my work
done. Two days later I found a workaround (turned out it was a
kernel problem, and using the previous kernel made X work); it was a
week or two before Debian fixed the problem with a new kernel release.

        ...Akkana