[SoaS] F12/soas use of the new 'isohybrid' feature of sys/isolinux

[Douglas McClendon]

Martin Dengler wrote:
> On Tue, Sep 29, 2009 at 09:51:47PM -0600, Douglas McClendon wrote:

>> On a completely random note ... I think it is
>> worth highlighting the new isohybrid feature of LiveCD/USB that is
>> new in Fedora 12.
> 
> I'd love to get more familiar with this.

I don't know much more than what it says here- (search for isohybrid)

http://syslinux.zytor.com/wiki/index.php/Doc/isolinux

I noticed the use of isohybrid in fedora's livecd-tools then found that. 
  Note that this does not obsolete liveusb-creator/livecd-iso-to-disk, 
it is just an alternate method of creating the liveusb.  Also, it should 
be noted for the non-technical, that unlike those other tools, this is 
necessarily a 'destructive' install.  I.e. it is clearly overwriting the 
partition table on the stick and the first several hundred megs. 
Instead of just adding files to an already existing fat/ext... 
filesystem.  Note also that as I said that using _this_ method will 
not(?) support persistence without new tools/support, despite the page 
above specifically mentioning persistence.  What the page really means 
is 'you can go do some stuff if you want', but currently there are no 
tools that make doing that stuff easy or even possible.  But I could 
write them, or give an interested party an outline of how to.  Or 
rather, here is the broadest outline-

a) generate and boot a liveusb stick in this fashion
b) once booted, use fdisk/whatever to create a second partition taking 
up the remaining space (I'm still curious what the initial partiton 
table looks like in this case)
c)format and mount the new partition
d)initialize a persistent overlay file (i.e. big zero-filled file) in 
the new partition's filesystem
e)live migrate the in-ram overlay to the new persistence file
   (you'll need to read and really completely understand 
/usr/sbin/zyx-liveinstaller-cli to do this)
f) write a script and even a gui to automate a-e and get it included in 
the next build of the iso so that users can easily optionally do the 
above in a pushbutton simple way.


> 
>> On another random note, my $0.02 is that the fedora based soas
>> should be referred to as a 'derivative distribution' or 'fedora
>> derived distribution'.  That captures the scope of both how it is a
>> distribution, and yet does not require the traditional level of
>> support and development of a 'non-derived distribution' (as if there
>> really is such a thing anymore, but here we mean 'lightly derived
>> distribution').
> 
> I encourage you to insert these comments in the discussion at the
> place you feel most appropriate.

I don't really want to get into the debate, I just wanted someone in the 
debate to ingest the opinion.  Mission accomplished :)

-dmc