Removing a shard has two different phases: 1) draining all the data from the shard being removed and 2) commiting the operation.

Right now we don't provide any hint about how to move the data of track unsharded collections: due to its current implementation their are considered as if they were sharded, waiting until their only chunk is "moved". However, this  won't happen as a regular sharded collection via moveChunk (and automatically done by the Balancer in most of the cases) but via moveCollection.

The purpose of this ticket is to provide more useful information about which data is still pending to be moved and which operations are expected to be used.