Very slow start with many zones

Hello.

Installed Knot DNS, version 2.1.0-dev from git master (commit bd3360db).
OS debian 8.

I add 230 000+ zones. When knot start it load zones without hight load, but very slow. With 230K+ zones knot started 3h 16m, and when all zones not loaded knot not response for 53 port and for knotc.

2015-07-31T13:18:34 info: starting server
...
2015-07-31T16:34:43 info: server started in the foreground, PID 12048
2015-07-31T16:34:43 info: remote control, binding to '/run/knot/knot.sock'