Scyld and fstab for Diskless slaves

[Daniel Ridge]

Chip,

On Tue, 19 Dec 2000, Chip Coldwell wrote:

> Interesting, so what is the mechanism for transmitting the compressed
> root filesystem image to the node, if not tftp?  I suppose you could
> configure the kernel to mount an NFS filesystem, retrieve a compressed
> filesystem image from it, expand it into a ramdisk, and then remount
> the result as /, but that's pretty kludgey.

The long answer to this question is contained in a couple of places --
our documentation and the list archives. I'm afraid that the burdens of
the holiday season leave me without the time to include them here.

The short answer is that we use TCP. We have a daemon that spits out
ramdisk images and kernels. This magic is all contained in our
'beoboot' package.

> software.  In particular, I'm planning to spec nodes that have no
> local persistant storae whatsoever, i.e. no hard disk, no floppy and
> no cd-rom (the less there is, the less there is to go wrong).  I know
> this configuration will work with my NFS-root diskless configuration
> because I've done it, but I like your ramdisk system better when the
> network is the bottleneck (and mine better when memory is ...).

Do you PXE boot?

As I have mentioned before in this forum, I think our solution is better
when networking is the bottleneck and also when memory is the bottleneck.
I can get the footprint of our software down to a couple of megabytes --
as our root filesystems can be extremely tiny. We have no '/bin' for
instance. 

If you're interested in just how small we can make this, there are a
number of posts on this topic in the list archives at www.beowulf.org

Regards,
	Dan Ridge
	Scyld Computing Corporation