Subject: Re: connecting multiple machines to a single SCSI disk ?
To: None <netbsd@vu.com, curt@portal.ca>
From: Patrick Arnoux <parnoux@orli.com>
List: port-i386
Date: 12/09/1995 05:32:42
On Fri, 8 Dec 1995, Curt Sampson wrote:
>
> > could i have each machine boot and run from a seperate
> > partition on the single SCSI disk?
>
> This is rather more difficult. You can't have more than one disklabel
> on a disk, and all of the machines will want to mount root from
> sd0a and swap from sd0b, unless you modify the kernel. You might
> be able to do three machines with root/swap on sd0a/sd0b, sd0e/sd0f,
> and sd0g/sd0h if you compile separate kernels for each. You can't
> use sd0c/sd0d because these are generally used for the NetBSD
> portion of the disk and the whole disk respectively (or is it the
> other way around?). You also *must* make sure that no machine writes
> to a partition in use by another machine, or disaster will certainly
> result!
Since in all probabilities, the SCSI driver will have to be modified
in order to be able to handle the contention between the different
bus masters, each kernel could also be setup to operate at a separate
cylinder offset and said offset could be dynamically allocated by
having an offset table in sector 0/0/0 maybe so as not to hard code
it into each kernel.
Have you considered Ethernet :)
Patrick Arnoux