Use the attached script to create the database/collection. Read the comments at the head of the file for directions.

When mongod and mongos are started without --keyFile everything works fine:

$ ./mongodump -d authtest
connected to: 127.0.0.1
DATABASE: authtest to dump/authtest
authtest.system.indexes to dump/authtest/system.indexes.bson
4 objects
authtest.things to dump/authtest/things.bson
100000 objects
authtest.system.users to dump/authtest/system.users.bson
1 objects

When mongod and mongos are started with --keyFile mongodump stalls dumping the actual documents:

$ ./mongodump -d authtest -u theadmin -p adminpass
connected to: 127.0.0.1
DATABASE: authtest to dump/authtest
authtest.system.indexes to dump/authtest/system.indexes.bson
4 objects
authtest.things to dump/authtest/things.bson