Subject: Re: SCSI disks for news server
To: Thomas Boroske <y0001006@ws.rz.tu-bs.de>
From: Ale Terlevich <A.I.Terlevich@durham.ac.uk>
List: port-arm32
Date: 01/14/1997 12:20:48
On Mon, 13 Jan 1997, Thomas Boroske wrote:

> Or another thought: If someone could tell me if a system running from 
> a powertec controller (SA RiscPC 600, 42MB RAM) would be usuable at 
> all, then I could even wait longer for a better support and use RiscBSD 
> nevertheless. Or would it be possible to use the old 210 MB IDE disc
> (not very fast, but probably faster than a powertec controlled disc ATM) 
> to store the most important parts of RiscBSD on it and use the SCSI disc
> for everything else ?
>               

  Ok. This is probably posible, but it's ANNOYING!

I had a similar setup to what you suggest above, but I've got a 420MB IDE 
disk and a cumana SCSI II card (works the same as the powertec).

  I have my entire IDE disk for RiscBSD plus 200Mb of the SCSI.  I at 
first tried having the important parts of the system on IDE, and less 
important things on the SCSI (like kernel sources, emacs and TeX) and 
this certainly works.

  What's ANNOYING is that the problem with these drivers isn't just the 
slow transfer rates, but also the fact that because they poll the 
hardware, they really hog the CPU, so for instance while compiling a new 
kernel I couldn't really do anything else, no matter now nice I made the 
compiling task.

  Now I use the SCSI disk as temp storage for data. If I want to work on 
it I copy it onto my IDE disk, then back when it's finished.

(It's also used to boot off, as you need to have an ADFS partition on a 
disk for unixfs to be able to use it it seems - unixfs doesn't see my 
entirely RiscBSD IDE disk)

  If you only have a 210Mb IDE then you'll need more if the 'vital' 
system on your SCSI.  It will be useable, but a pain.

  Hope this ramble is of some use!

Ale.