This sort of power-up interdependency is a royal pain when managing a large installation. As Bruce notes, moving key data like DNS and NIS off the filer to local disk goes against the idea of having all of your data in a central, secure place.
Right.
The very fact not everyone immediately sees the dependancy underlines my point. If Netapp wants to provide a simple, robust, reliable storage solution, that sometimes means including a few "auxilliary" services that may be required to perform this function. We don't want customers bitten by subtle bugs if it can be avoided, and NIS slave functionality is a small change purely for the filer's benefit; I'm not suggesting Netapp start making NIS appliances. :) (Although a DNS/NIS/WINS/LDAP/etc. appliance does have some appeal....)
Bruce