scyld scsi support

[Daniel Ridge]

Mitch,

> just about to get started with scyld cluster (once i receive the cdrom
> from linuxcentral).
> recommended hardware lists IDE, but no SCSI.
> 
> is SCSI supported for the boot disk?

SCSI usually works just fine with the Scyld Beowulf software -- although
the level of 'support' provided with the $2.00 CD is 'label side up'.

I'm not sure what you mean by the 'boot disk'. If you mean the CD as
used to install the master, then yes. If you mean the CD (or node floppy)
as used to boot the nodes, then sort-of.

The Scyld node boot process has a number of different phases that come
into play here. The first kernel we boot doesn't know anything about SCSI
-- cheer up -- it doesn't know anything about IDE either. All it knows how
to do is grab a kernel over the network and jump to it (via 2-kernel
monte).

The second-phase kernel can (and by default does) support SCSI. You can 
also use tools like 'insmod' and 'modprobe' to plug new modules into node
kernels after your nodes are up. Under scyld, 'insmod' and 'modprobe' take
the additional argument '--node <num>' and use this as a target kernel to
insert modules into.

Regards,
	Dan Ridge
	Scyld Computing Corporation