This only fails for collections with no _id index. Such collections are not created by default in version 2.4+.

Discussion here: https://groups.google.com/d/topic/mongodb-user/uC4bYdbmabM/discussion

In a replicaset it's not possible to set the notablescans flag on the master because the slaves are unable to read capped collections.

Here is the corresponding part of the log:

> Tue Jan 17 20:00:23 [rsSync] replSet initial sync cloning db: admin
> Tue Jan 17 20:00:24 [rsSync] replSet initial sync cloning db: config
> Tue Jan 17 20:00:24 [rsSync] replSet initial sync query minValid
> Tue Jan 17 20:00:32 [rsSync] replSet initial oplog application from a2.serv:27017 starting at Jan 17 07:03:38:6 to Jan 17 20:00:24:8
> Tue Jan 17 20:00:33 [rsSync] replSet initial sync failing, error applying oplog 10111 table scans not allowed:myDatabase.myCappedCollection
> Tue Jan 17 20:00:33 [rsSync] replSet initial sync failed during applyoplog