considering root mounting /dev/ramdisk

["Anders E. Topper" <topper@link.no>]

Hi,

I have run netboot and root mounted a filesystem using NFS for quite
some time.
Now, I'd like to try running a Linux system off a ramdisk still while
using netboot.

I have just started looking into this, and am wondering if anyone who
has done
this before could give some feedback on the project outlined below. This
posting
might be slightly off topic, because it is more about using netboot than
having
netboot up and running, technically.

The goal is to have one machine running all diskless, not even dependent

on disks via the network (NFS, et.c.). It will only be allowed remote
disk
access while booting and initializing.

I'm considering the following way to set this up:
("The diskless box" is from now called "the client.)

- Client loads the netboot image (floppy or ROM), then downloads the
kernel and a ramdisk image from
a NFS server. Client boots the kernel and mounts the (now uncompressed)
ramdisk image as root.

(So far I'm  just using netboot the way it works.)

- INIT sets up (say) runlevel 1, which starts /bin/sh and gives a
console, and then...

- copies client files from a remote server into the ramdisk(s). The
client has
176 MB, and perhaps 100MB of files could be downloaded. (compression
here can
be added later)

- INIT is told to change to a higher runlevel, and will then run a more
fully fledged
set of start-up routines, now that the ramdisk(s) have about the same
contents as
a more standard linux distribution.

- The Client now has got a fully working Linux system in ramdisks and
remote servers
can be unmounted.


Comments much appreciated. I am, among other things, wondering how
big an initial ramdisk image I should go for, what it just has to bring
along and
what can wait until the files are being copied from remote server.


Cheers,

Anders E. Topper