Custom build your very own Live Linux (long)

[Antonio T. Sun]

[WARNING: this is a long post]

Hi, 

I believe that most of us have a few Linux Live CDs handy, but
have you thought of creating your own Live Linux systems with
your own choices of tools, preferences, and docs?

Read on if you answer yes to any of the following questions:

- Have you ever hope that your favourite Live CDs include that
  extra tool that you love?

- On the other hand, did you ever feel that it is a waste of
  space for general purpose Live CDs to include 2 file managers,
  3 email clients, 5 window managers and 7 text editors?

- For those Live CDs that include one and only one tool for each
  task, did you ever feel uncomfortable that someone else is
  making the decision for you?

Ok, I know that people know a lot of such Live CDs building
tools. For example, grml-live from GRML will allow you to 
*custom build* a Live CDs *in a single command*. 
This is not news at all. I'm talking something new today --


These are what grml users had been asking/longing for:

  On Sun, 08 Mar 2009 15:32:01 +0100, Lars-Erik Helander wrote:

  > Regarding the persistence solution, I think I would rather like to 
have
  > a solution where the installed packages are not forced to be loaded 
into
  > main memory - as I understand that the live-snapshot would do, or ...?
  > Do grml have some toolchain that will allow me to either add stuff to 
an
  > existing squashfs or have the system "union mount" additional squashfs
  > files?

  * Michael Schierl <schierlm-public <at> gmx.de> [20061105 19:15]:

  > . . .  I want to carry around as few disks
  > as possible. So I thought if it is possible to splitting the squashfs
  > image into two images that are merged by unionfs, where the smaller
  > one contains a basic system that includes all stuff from grml-small
  > (which may be larger than 50MB, but as small as possible) and have a
  > cheatcode to load only the small part into ram (and not use the large
  > part at all). I do not know if this is feasible . . . 

but the answer isn't available up until now -- now, you can build
a stacked Debian Live system with the help of aufs + grml
tools.

But why "stacked" you may ask first. 

If grml is build on top of grml-medium, which is build on top of
grml-small, then putting all 3 flavor on the same USB would not
cost you more than one CD space, whereas currently it almost
needs two.

Another great advantage is that, I never need to remaster my live
system any more just for my own customization -- putting my extra
stuff in is just as simple as putting in several modules. My
live-usb always contains the latest tools/docs of my own, without
going through the live system remastering process. I had about 7
layered modules that I build for slax and I just put them on top
of grml. It works perfectly.

Further, with stacked live system, you can, for the first time,
load grml-small into ram (or grml-medium depending on your ram
size), and leave the rest on USB/CD.

Most importantly, it’ll be much faster. Suppose your stacked live
system is layered like the following:

   1. All console tools
   2. Xorg + lightweight window manager + essential X tools like gparted
   3. Heavy weight desktop system (Gnome/Kde)
   4. Occasionally used applications (OOffice/Latex)

If you limit your self to only certain tasks (say console-only
hacks), then you only need a limited number of modules to be
loaded; all other modules are not loaded on start up. hence it
will start faster, use less ram, and cause applications to run
faster. Moreover your CD drive will only seek in a small
area (instead of all across the whole CD). You don’t even need to
load it to ram if the loaded modules can be fully cached by the
kernel. This significantly improves the speed. On the other hand,
you can enjoy the full fledged desktop applications if you want
to, from the very same CD.

Furthermore, from the practical point of view, 

   1.  it might not be that easy to get everything straight out
   when you first try grml-live. So it is better to start small
   at first. My first layer is only about 100M big, so it is much
   faster to build than going for the whole 700M CD, considering
   you need to run it over and over to get it perfect. If you
   have successful gained a solid ground, you can then go one
   step further. Having such stacked framework enable you try
   each step individually, if you screw it, you don’t need to
   start all over again.

   2. having such stacked framework makes it possible for my own
   system customizations to survive system upgrading. I just need
   to make customized changes to my own system once and only
   once (for example setting up an anonymous ftp uploading
   capability with write-only no-read-back access). Then no
   matter how many brand-new installations I do later on, I don’t
   need to do such customizations again, because my
   customizations stay on the upper level than the installed
   system.

If this seems interesting to you, please head to
http://wiki.grml.org/doku.php?id=stacked_grml
and read the complete solution.

Thanks


--
The Toronto Linux Users Group.      Meetings: http://gtalug.org/
TLUG requests: Linux topics, No HTML, wrap text below 80 columns
How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists