In the documentation topic on setting up an Umbraco load-balanced solution here:

http://our.umbraco.org/documentation/installation/load-balancing

It mentions this, under the file replication setup option:

"When running in a replicated environment Lucene/Examine indexes must not be replicated"

My question is "why?" I'm curious to know what the possible risk is for doing this. We've setup DFS for the indexes because we don't want the indexes to get out of date if a server is offline during a publish (distributed call) operation.

So far our testing shows that this works fine. Before we invest in the time in setting up a system to ensure that all the application servers are only ever talking to a single file server, I'd like to understand the risks better.

Thanks!