broken install.cfg for sysinstall

[Geoff Sweet]

I'm trying desperately to make my install.cfg file work.  Documentation 
is sparse online and based on the few examples I have been able to find 
I can created this:

---
debug=yes

hostname=newserv
domainname=x10.com
nameserver=10.16.0.2
defaultrouter=10.16.0.1
ipaddr=10.16.0.254
netmask=255.255.255.0

mediaSetCDROM

distSetEverything

disk=da0
partition=all
bootManager=boot
diskPartitionEditor
da0s1a=ufs 4194304 /
da0s1b=swap 4194304
da0s1d=ufs 4194304 /home
da0s1e=ufs 4194304 /tmp
da0s1f=ufs 8388608 /usr
da0s1g=ufs 8388608 /usr/local
da0s1h=ufs 0 /var
diskLabelEditor
diskPartitionWrite
diskLabelCommit

installCommit

shutdown
---

yet when I load that config from the installer booted off the CD, it 
loads the file, prompts me to remove it from the floppy, then throws the 
message:

"No root device found - you must label a partition as / in the label editor"

But I can't find any examples of how to make that happen.  Can't someone 
offer some insight?  I have about 60 servers to install and even getting 
this basic install.cfg file will be a big help.

-Geoff Sweet