// Set up a sharding test. var st = new ShardingTest({ shards : 4, mongos: 1, chunksize : 64, config : 1, other : { nopreallocj : 1 }}); st.adminCommand( { enablesharding:"test" } ); st.adminCommand( { shardcollection:"test.hashed", key: { _id: 'hashed' } } ); function insertData(db, colName, num, w) {     start=db.serverStatus().uptimeMillis;     col = db.getCollection(colName); col.remove();     for (i = 0; i < num; i++) {         col.insert({_id: Math.random()});         db.getLastErrorObj(w); // call gle safe     }     end=db.serverStatus().uptimeMillis;     return ((num*1000)/(end-start)); } // num = 50000; hashed=insertData(db.getSiblingDB( "test" ), 'hashed', num,1);