Samba 4 reverting to Bind9 from the internal backend

[Mike Howard]

What's the recommended procedure for reverting to Bind9 after initially 
provisioning the internal dns backend?

I was hoping it was as simple as 'server services = -dns' and running 
'samba_dnsupgrade' followed by a samba restart but I've been away from 
samba4 for a little while.

'samba_dnsupgrade'  doesn't even exist on my install (Version 4.0.5).

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