Subject: Re: Serial speeds, and SCSI probs
To: Aaron S. Magill <amagill@uiuc.edu>
From: Bill Studenmund <wrstuden@loki.stanford.edu>
List: port-mac68k
Date: 02/16/1996 09:34:09
> 
> This is really two unrelated questions, but it is late, and I don't feel
> like seperating it into two messages, so there! ;-)
> 
> First, most of the chat/ppp scripts I come across related to macBSD all use
> 38400 as the baud rate, rather than 57600... I know the kernel will support
> 57600, as I use it myself right now, but I was wondering if there was a
> reason other than the fact that not all systems (i386 comes to mind)
> support 57600.

How fast is the modem? With data compression, you  get about 3x or 4x
over the raw data rate. Thus my 14400 can get about 3kB/sec rates.
38400 meshes with this rate nicely. Going to 57600 gains nothing, and
reduces the flexability of the kernel to respond to interrupts (as it
has to respond as fast as the characters arrive). As I've said before,
the serial ports are "use at your own risk" above say 28800. Note:
for sending, they're fine up to 57600. And reception should now
be fine at 57600, just you'll load the machine a lot.

> And second, I supped the kernel sources yesturday (Feb 14) and rebuilt the
> kernel... now when I boot up, I can get to single user mode, but if I try
> to boot into multi-user mode, I get messages about sd0g not being
> configured (sd1g and sd2g give me the same problem.).  Next I see messages
> about needing to run FSCK by hand (I assume because it can't read the
> non-configured sd0,1, and 2)
> 
> Then, it locks up.  No debugger, no prompt, no messages, no nutin.

The scsi drives are coming up numbered the same as before?

> If I go into single user mode and put the old kernel back (backups are
> wonderfull!) and then reboot, viola... everything works again.

You overwrote a good kernel with a test kernel? Tisk, tisk! My root
has about 5 kernels scattered around at the moment. One works, one
is netbsd (a link to whatever's running so ifconfig works), and the
others are various debug kernels.

> If it matters, this is running on a Mac IIx w/ 8mb of ram, and three harddrives
> (one for / and /usr, one for /var, and one for random data...  The root
> drive has 3 partitions (1 mac, 1 / and 1 /usr) and the other 2 just have 1
> partition each.)
> 
> Any thoughts?

Is disklabel staticly linked? The partition mounting code was recently
changed, so you might be getting partitons in new places. The problem
might be that you seem to have a /usr partiton, and most commands need
the shared libraries in /usr/lib. :-(

disklabel should be able to tell you were the partitions are placing
themselves. Then a quick fix to /etc/fstab, and you're done.

Take care,

Bill