Fixed knot.full.conf for zonefile-sync.

samples/knot.full.conf

@@ -238,9 +238,11 @@ zones {
 
   # Timeout for syncing changes from zone database to zonefile
   # Possible values: <1..INT_MAX> (seconds)
-  # Default value: 1h (1 hour)
+  # Default value: 0s - immediate sync
   # It is also possible to suffix with unit size [s/m/h/d]
   # f.e. 1s = 1 day, 1m = 1 minute, 1h = 1 hour, 1d = 1 day
+  # Warning: If serving a large zone, set this to a larger value
+  #          to keep disk load down.
   zonefile-sync 1h;
 
   # File size limit for IXFR journal