[sf-lug] Multiboot

[aaronco36]

Quoting Michael Paoli <Michael.Paoli at cal.berkeley.edu>:
> I've done it* ... but relatively rarely and only when I
> had quite compelling reasons* to do so.  I wouldn't
> recommend it for most nor in most circumstances.
>
> Some of the many hazards, are updates on either/any
> installed OS, there's always significant risk of it
> screwing things up - most notably for the other OS, ...

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.

Heck, don't even need an SSD to install two or more Linux distros on 
separate partitions within a single 160 GB (149 GiB) or larger spinning 
rusting disk drive. Can just partition something like the following where 
/dev/sda is a low-end 160 GB specifically set up and dedicated just for 
such a multiboot purpose:
/dev/sda1 -- 1.000 GB /boot
/dev/sda2 -- swap x 1.5 (e.g., 6 GB for 4 GB physRAM)
/dev/sda3 -- 140 GB+ Extended
/dev/sda5 -- 30 GB as distro-1's /
/dev/sda6 -- 30 GB as distro-2's /
/dev/sda7 -- 30 GB as distro-3's /
/dev/sda8 -- 90 GB+ as distro-1's /home and as distro-2's + distro-3's /shared

Admitted Multiboot Addict here ;-D

I've found at least these key points when installing multiboot distros in 
scenarios such as the above using a 160 GB drive ...
a) rigorously and redundantly backup the /boot/grub/grub.cfg file to a 
somewhat similarly-named /boot/grub *.cfg file after each successful 
distro installation and full upgrade
b) keep careful track of each distro's Linux kernel name+version upon 
installation and upon any and all of that distro's upgrades 
Installed kernels will be present in /boot along with their associated 
initrd, config, System.map, and other files
c) keep careful track of all drive partitions' UUIDs (i.e., UUIDs for for 
/dev/sda5, for /dev/sda6, for /dev/sda7,...etc) following each distro's 
installation, e.g., using 'blkid /dev/sda'
d) Generally-speaking and IMOE, things get exponentially more complex 
having to manage and upgrade a handful or more separate distros installed 
in a multiboot fashion on one computer and using one /boot partition (and 
re-using its single grub.cfg file) as in the above scenario :-\

My own "magic number" of fully-manageable and upgradable multiboot distros 
is three, unless there are compelling reasons to increase this (which 
still happens frequently enough, BTW), but definitely YMMV.

Wish to see a few multiboot case examples in my next reply/replies ?


aaronco36 at sdf.org