Optimising pxeboot disk size

[Bernard Dugas]

Wojciech Puchar wrote:
> i already did such things but with NetBSD 1.5 for my Xterminal distro.
> 
> it's simple:

More simple when you tell it ;-) Thanks a lot, i will try it tonight !

> I wish it's helpful, doing this doesn't just save space but saves time - 
> you have to upgrade software once.

So preserving consistency, which is the most important when you have lot 
of diskless stations !

> you may like to make /etc-common directory and put most of files there, 
> and symlinks in each station's /etc

In fact, it makes me think that we miss a concept in mount, or at least 
i don't know it currently :
imagine a -tl (TransparentLayer) option for mount, allowing to mount 
multiple source to the same directory, for instance /etc :

mount -r yournfsserver:/basic/etc /etc
mount -tl -r yournfsserver:/TypeX/etc /etc
mount -tl -r yournfsserver:/StationY/etc /etc

A file is first look for in yournfsserver:/StationY/etc,
then in yournfsserver:/TypeX/etc
and finally in yournfsserver:/basic/etc.

This means that StationX will see in its /etc firts its specific files, 
then the files dedicated to TypeX station (webserver, dns server, 
workstation,...) and then all basic files unchanged from standard 
distribution.

When you want to change something, you add a rw TransparentLayer :
mount -tl yournfsserver:/StationYchanges/etc /etc

So that changed or added files are only stored in this rw partition, 
thus very small and easy to manage.

This would be a kind of partition inheritance, like in object 
languages... Dreams are allowed :-)

Thanks a lot,
Best regards,
-- 
Bernard DUGAS Mobile +33 615 333 770