error messages from Adaptec driver when installing system

[Paul Borman prb@bsdi.com]

> From: Steve Kotsopoulos <steve@ecf.toronto.edu>
> I did that, and got:
> 
> adaptec0:invdcmd #01, len 5
> scsiwait timed out
> adaptec0:invdcmd #02, len 1
> scsiwait timed out

The first three things to do when having SCSI problems:

1) Check your cables and terminators
2) Check your cables and terminators
3) Check your cables and terminators

We have found under BSD/OS that this is the single largest cause of
weird SCSI problems.  Active terminators are best.  If you run external
cables you need to get high quality ones.  We did discover that with
adaptec and poorer quality terminators (like the ones that come on most
disk drives) that if you had an internal and external chain that you
had to leave the terminators in the card (so you would have 3 sets).
This is clearly wrong, but it is what it took for some combinations.
Also, don't crank of the speed on the card.

				-Paul Borman