howto improve speed of lh build with more RAM

[Jonas Stein <news@jonasstein.de>]

Hi,

i want to speed up the generation of new debianlive images.
At the moment it takes 2.5 hours to build a 4 GB System an put it into 
an squashfs.

The CPU utilisation was not 100%. The HDD seems to be the bottleneck.

I have installed 8 GB RAM now. My idea was to make a 6 GB ramdisk with 
kernelmodule brd.
I want lh build to use this ramdisk for chroot.
My first idea was to

mount /dev/ram0 /var/local/deblive/chroot

cd /var/local/deblive
lh config ...
lh build

but lh build wants to delete chroot. Who has an idea, how i can make 
best effort with the RAM to improve the speed during build process?

--
Kind regards,

Jonas Stein