[LAU] all in ram?

[Cedric Roux]

----- "alex stone" <compose59 at gmail.com> wrote:

> I should add here, i'd still have the OS and LS on a HD in the sampler
> box. But i'd like to have the whole thing run in ram, and boot only
> from the HD.
> 
> Alex.

I never did such a thing, but here is how I would try:
1 - compile the kernel to only put what I need to let the hardware
    run (so no modules for example, and only the file
    system drivers for the harddisk, initrd, ramdisk)
2 - make an initrd disk with a small system

The initrd minimal system would:
3 - format a ramdisk file system "big enough"
    (that depends on your setup)
4 - copy everything from the HD to this ramdisk
5 - do some kind of chroot and run you LS stuff

And roll on.
Step 4 might take a while.
Or not.
You have to mount the harddisk, then cp all,
then umount the harddisk. If you don't umount
maybe things will boot faster but there might
be some disk latency at the beginning for the
kernel has to copy data from harddisk to memory
when you use it the first time. So I think
you want to umount.

How minimal can the initrd be? Very. It
doesn't have a lot of things to do. Since
you know your hardware you can bypass a lot
of tools run at startup by big distributions.
(I have a bad internet access, so I can't look
for links, but it should not be too hard. Knoppix
has an initrd, so does Debian, IIRC. There must
some good doc somewhere.)

Just my fews cents.

Bon courage !
Cédric.