One of the common complaints we've received over the years about BIND 9 is that large authoritative servers, particularly those with a very large number of small zones, are slow to launch. I've met some DNS operators who expressed a powerful aversion to upgrading their systems, because a shutdown and restart can literally take all day.
If that describes you, I have some good news. There is a simple optimization for BIND 9 that can dramatically improve your startup performance.
