venti is currently optional--i don't use it yet myself--and factotum looks
after itself (you'll see a few different prompts, but otherwise it
doesn't require care and attention).  one difference for
authentication is that authdom= auth= pairs are needed in
/lib/ndb/local for each authentication domain you need.
	auth=sources.cs.bell-labs.com authdom=outside.plan9.bell-labs.com
for instance.

if you've written your own file servers, you'll have some work to do.
there are big differences in the C libraries and programming
interface.  see /sys/doc/release4.ps and /sys/doc/prog4.ps
to see where to start.

the file server kernel source is a little more convenient for configuration
compared to the previous release.