dhclient acts odd with read-only '/' & other questions about /dev

[J. Seth Henry]

Ok, I think I just qualified for an idiot award. After a little more
poking around, I discovered that it was the read-only filesystem that was
causing the problem. I rebuilt the microdrive image, and included a
special /dev this time - which I mount over the original /dev.  Now, I
don't seem to be having any problems with sshd.

Unfortunately, I appear to have made my dhclient problem worse. Now, it
hangs, producing volumes of log data like this:

Apr  3 17:52:45  dhclient: New IP Address (aue0): 192.168.1.5
Apr  3 17:52:45  dhclient: New Subnet Mask (aue0): 255.255.255.0
Apr  3 17:52:45  dhclient: New Broadcast Address (aue0): 192.168.1.255
Apr  3 17:52:45  dhclient: New Routers: 192.168.1.254
Apr  3 17:52:45  dhclient: New Network Number: 192.168.1.0
Apr  3 17:52:45  dhclient: New Broadcast Address: 192.168.1.255
Apr  3 17:52:45  dhclient: New IP Address (aue0): 192.168.1.5
Apr  3 17:52:45  dhclient: New Subnet Mask (aue0): 255.255.255.0
Apr  3 17:52:45  dhclient: New Broadcast Address (aue0): 192.168.1.255
Apr  3 17:52:45  dhclient: New Routers: 192.168.1.254

I have to hit CTRL-C to get a login...

I tried running dhclient under truss, but it gives me a segmentation fault
before getting very far. It doesn't seem to be attempting to write to
files on a read-only filesystem though. I can post the output of truss if
anyone is interested.

Also, on a slightly related note, I noted that mount_devfs wasn't on my
system. Is this not present in 4.7, or did I miss something? It seems
like that would be a better way to handle this situation, particularly since
the microdrive is a slow, and twitchy, device. I think a rash of nasty
crashes I had the last time I got this far was due to /dev being on the
microdrive. I've already had one strange crash since mounting /dev from
the microdrive - which given the history of this project - would indicate
that the system doesn't like having the kernel interface mounted from
there.

This is a  shame, as the system was very stable with /dev on the flash
disk. That said, is there a way to create a memory disk just for /dev, and
if so, how are the device nodes built? I can't netboot, because of the
USB NIC, but I do have the onboard flash disk. As for the memory disk, do
the same newfs parameters apply? I had to specify 'newfs -b 8192 -i 16' to
get all the inodes I needed for /dev.

I'm willing to give 5.0 a shot, but I spent a pretty good bit of time
paring down 4.7 to fit in such a small space. I'm not sure if 5.0, with
all its new features, would be as easy to squeeze. (4.7 just barely fits
on a 16Mb flash and a 340Mb microdrive) I'm even down to tweaking the
newfs paramaters to get stuff to fit.

Again, thanks for the help!
Seth Henry