title: Can I disable indexes on MongoDB master that is used for writes only?
body: <p>We have an application that uses MongoDB for log keeping. We run a pair of machines in replica set. One machine is used for writes, another for reads (reports and lookups).</p>
  
  <p>By looking at MongoDB docs I can see that there is a "buildIndexes" config option for replica set. 
  Is there a downside of disabling indexes on a machine that is only used for writes? Would I need to "lock" a machine in a replica set to be always Master?</p>
  
  <p><a href="http://www.mongodb.org/display/DOCS/Replica+Set+Configuration" rel="nofollow">http://www.mongodb.org/display/DOCS/Replica+Set+Configuration</a></p>