Some progress being made... Dual boot linices?

[Jarod Wilson]

On Tue, 2008-10-21 at 14:27 -0400, bruce.labitt at autoliv.com wrote:
> First off - my humble thanks to the wisdom of the list for helping me 
> along in this crazy journey.
> 
> My Cell blade processor now boots and runs YDL6.0.  Of course that is all 
> that it does at this point, eventually I will actually have to use it for 
> something besides a space heater...
> 
> When I was configuring the head node, (which is my desktop linux box), I 
> agreed to blow away my Ubuntu 8.04LTS x86_64 distro for CentOS5.2 x86_64. 
> This was to reduce the number of variables, so we could finally get things 
> going.  As I originally suspected, it was not the distro, nor the 
> configuration of the distro, in particular that was the issue.  It was a 
> quirk in the hardware... :0
> 
> I would really like to go back to Ubuntu.  It feels a lot more modern, and 
> it supports my video out of the box.  Can I install Ubuntu to be dual boot 
> with CentOS?

Yes.

> That way, if I need some additional vendor support I can 
> boot into CentOS, which is one of their supported distros.
> 
> >From http://brainstorm.ubuntu.com/idea/12364/ it appears that installation 
> of dual boot linices (linuxes?) is awkward.

Can be. Depends on how you go about it...

> Anyone installed ubuntu to be 
> dual boot with centos?  What do I look out for?

If you wanted to use a shared /boot between the two, it'd be a bit
messy... For one, Ubuntu uses menu.lst for its grub config, CentOS uses
grub.conf, with a menu.lst symlink to it, so depending on which distros
version of grub is actually installed into the boot sector...

What I'd do is have separate /boot partitions for each. Install Ubuntu
with /dev/sda1 as /boot, with grub installed into the MBR. Then install
CentOS with /dev/sda2 as its boot, and install grub into the beginning
of the partition, instead of the MBR. Now configure Ubuntu's grub to
chainload CentOS' grub on /dev/sda2. Then both can happily update their
boot menu options without stomping on one another.

> I looked at virtual box, and decided that it would be too complicated and 
> may represent a performance impact. 

Just started playing with virtualbox myself on some non-kvm-capable
hardware at home... CentOS runs TERRIBLY in it -- a completely idle
text-only guest consumes ~65-80% of one cpu on the host. Conversely, a
Fedora 9 virtual box guest w/X running consumes less than 2% cpu on the
host when its idle... VMware Server would likely be better suited for a
CentOS guest if you were to go that direction. Actual performance of the
Fedora 9 guest was pretty solid though, I wouldn't be too concerned
about performance with modern hardware (in my case, a ~3 year old dual
Opteron box).


-- 
Jarod Wilson
jarod at wilsonet.com