Kmeans clustering in multiple levels

[Veronica Joh]

Hi
In the manning book, it is suggested that we run clustering in multiple levels 
when clustering large number of articles.  For example, if we were to cluster 1 
million articles, we would first cluster it into 100 giant clusters and cluster 
again to get smaller clusters.
My question is when we run cluster for each level, what should be the 
maxIteration?  Is doing one iteration enough for each level?
Thank you,Veronica