Bring up master: mongod --master --dur
Bring up slave: mongod --slave --source <ip> --dur
Start loop inserting tiny objects: for (i=0 ; i < 4000000; i++) { var doc =

; db.stuff.insert(doc);}
kill -9 on master

Check num docs on slave:
> db.stuff.find().count()
636315

Bring up master and check num docs:
> db.stuff.find().count()
636102