Does anyone have any guidelines for "best practices" on a Novell DNS/DHCP

We are a large school district rapidly implementing DDNS, and I would like
to know if we are within recommended parameters for scalability.

We are currently using one DNS server with a passive failover DNS box to
service a projected 250 zones. What I'm most curious about is one particular
zone that looks like it might grow to around 10,000 records.

Can anyone offer any insight into an implementation of this size?