Re: [gentoo-user] installing gentoo (multiple OS)

[Mick]

As far as I know all/most of these OS will interfere with your MBR and 
potentially your /boot partition and install their boot code in there.  This 
is not a problem per se, as long as you are aware of it.  Booting from a 
LiveCD is all you will need to do to fix things.

Given the number of OS' that you want to play with I would strongly advise to 
consider using virtualbox or any similar virtual machine, running in your 
favourite OS (e.g. Debian as the host) and then create VM images for each 
guest OS that you want installed.  Performance will be only slightly slower 
than booting into these OS separately from BIOS, but on the other hand you 
won't need to be repartitioning or zeroing/formatting partitions when you want 
to get rid of an OS.  Also, you may end up running out of partitions - I think 
SATA used to read up to 15 partitions only.  So, with virtualbox you can add 
new OS images at a click of a button, instead of creating new partitions, 
moving partitions around and what not.  LVM will help with sizing partitions 
on the fly, but will add another layer of complexity.


Before I give specific OS suggestions below, let me propose a booting 
architecture for separate partitions for you to consider:

Create one 'master' boot partition and install GRUB in it with a LiveCD.  I'd 
use legacy GRUB because it is simpler, slimmer and easy to fix.  Others may 
recommend GRUB2, which installs what looks to me like a mini OS in itself and 
automates a lot of the configuration.  I've been less successful editing the 
boot options from the command line at boot time with GRUB2, but it is more 
stable these days.  Anyway, both will work fine.  Never delete this GRUB master 
partition, or you will need a LiveCD to be able to boot again.

I'd create one swap partition for all OS except MSWindows, which will create 
its own paging file, fragment its own NTFS fs, corrupt this paging file without 
any help from you and then use up all the partition space and crash!  ha, ha, 
ha! :))  Well, it's not always that bad, but it has happened here more than 
once.

With the disk space available to you, you may create more than one swap 
partition.  I seem to recall (could be wrong) with 32bit OS that 128M was the 
amount that would be accessed at a time by the kernel or something similar - 
so people used to create multiple 128M swap partitions.  These days with 64bit 
OS and large RAM modules you may not need swap at all, unless you start 
running http servers, big databases, etc.  In any case, I'd set up a 2G swap 
as a minimum and up to the size of your RAM as a maximum.

Then if you decide to have separate real partitions on the disk for each OS 
instead of VM images, I would install each OS in their own partition without a 
separate boot partition for each, to keep the number of partitions down.  You 
will then be able to chainload from your master boot menu.lst any OS boot 
system.

If you will prefer to dual boot MSWindows and at least one main Linux system 
(which will host your virtual machines) I would refrain from using the 
MSWindows OS boot system to chainload Linux from it - because it is 
complicated and messy:

http://thread.gmane.org/gmane.linux.gentoo.user/226452

Specifics below.

PS.  I merely express a view here - how I would go about it.  There are 
probably as many views on the things I suggest above as readers on this 
mailing list.  Thankfully with Linux there's more than one way to skin a cat.

PPS.  No cats were harmed in preparing these suggestions!  LOL!  :))

On Sunday 04 Dec 2011 08:21:52 srini srini wrote:
> @MIck
>
> I have a 1TB seagate disk drive, which I would like to install...
>
> 1. Will also have windoze whatever bs it is, since its usage is still in
> existence duh! -  -

If you don't install this/these OS' in a VM, then bear in mind that Vista and 
Windows 7 create a separate hidden 200MB boot partition.  This will eat up one 
more partition out of the 15 physical partitions on your SATA drive (you can 
use LVM if you're planning to exceed the 15).


> 2. Surely Debian the universal OS  - will have x86-64 image. - GNOME -
> Kernel 3.x. - bash

This can be a workhorse for your guest OS.  It doesn't change often and things 
should *just* work.

You can/should store the various OS' images on a separate physical partition.  
So you can always reinstall/upgrade your Debian without affecting all other OS.


> 3. The Ubuntu - will have 32-bit - image. - XFCE - Kernel 3.x. - bash
>
> 4. The Slackware vanilla (stable), to get deep into the kernel :) - 32-bit
> image - registers and argument handling. - fluxbox - Kernel 2.xx.x - bash

Fluxbox is slim but needs a lot of configuration to make it look nice.  I'd 
consider Englightenment (e17) from svn because it is both lighter on resources 
and looks nicer with minimal configuration.


> 5. Voiding Gentoo is like keeping the penguin out of ice cap, so will make
> space for it. -x86-32 image - KDE - Kernel 3.x. - sh

Your Gentoo will take more space than all the binary distros.  Depending on 
how many DEs you will install I'd bargain for 10-20G.

You could have a common home partition for your various OS', but I probably 
would not, since I would want to have separate user configurations of 
potentially the same apps.


> 6. Thinking of legacy commercial unix solaris 5/09 (the original unix of
> them all) - 32-bit image - CDE - woohoo!
>
> I know its a bit whimsical, but would love to work on these OS'es except
> the #1 in order.
>
> Yes I have a PC clone, thus MBR.
>
> Any advise is welcome.

HTH.
-- 
Regards,
Mick