crawl indexes and part-00000

[Brian Whitman]

I am looking for a simple explanation on what the "part-00000"  
directory in my craw/index folders are, and when they are created and  
when they are not.

I am having a bit of a trouble merging multiple nutch-created indexes  
using bin/nutch merge -- the merge tools seems to always expect the  
index directory to only have a "part-00000" folder in it with the  
actual lucene indexes below. For some reason, in my crawls I end up  
with some index dirs with the part-00000 and some index dirs without  
it. And so I get "IndexMerger: java.io.IOException: crawl/index/ 
_0.fnm not a directory"

How could this happen? Do all nutch index generation tools generate  
this part-00000 folder? Did something mess up up the chain? Will  
there ever be a part-00001? :)