[Samba] Speed of Samba internal DNS for AD

[Gregory Sloop]

So, I'm wondering how "fast" the Samba internal DNS server is. (not BIND DLZ, Samba Internal DNS) 
 
In the envisioned envoronment, lets say a few hundred clients across a campus. A pair of AD servers, running on VM's. 
(Lets just assume they'll have enough resources - if needed we'll give them more.)
 
Do I:
 
1) Point all clients at the AD DNS (Samba Internal DNS) as their primary and let the AD forwarders handle all other non AD queries.
or
2) Delegate my 3rd level domain (e.g. ad.somedomain.com) in my main BIND (not samba) servers to the AD servers for lookups and handle everything else on (non-samba) BIND.
 
If the volume of lookups that Samba internal dns can handle is perhaps an issue, the second approach would be far better, since it will place the least load on the AD/Samba servers  - they'll only handle lookups they are actually responsible for. (not doing any forwarding)
 
If the AD servers will have way more than adequate capacity, then #1 works fine.
 
So, what's that capacity actually look like in practice?
I don't know that I've seen any recent discussion about this on the list.
 
And perhaps rather than just addressing my proposed environment, how about the general case… 
When/where/how will Samba internal DNS start to fall apart?
 
-Greg