We use Mongodb 2.4.6
We added a new shard to our cluster. Each shard is a replica set with 3 nodes (2 powerful nodes and one backup hidden secondary)
We use tag aware sharding.
The new shard was added to a collection which was on 2 shards only before. So the data was balanced from 2 old nodes to the new one. 3 in total for this collection. Chunk size per shard is now equal (1172 each). On these shards there is only one collection (tag aware sharding).

But on one of the 2 old shards we see a lot cleanup messages in the log, thus we have high IO on this server

Tue Feb 18 11:15:33.860 [cleanupOldData-52f25c698cd98919080ca194] moveChunk deleted 124451 documents for database.collection from { targetUid: -5991322687277590967 } -> { targetUid: -5985241970436000175 }
Tue Feb 18 11:15:33.860 [cleanupOldData-52f25e478cd98919080ca199] moveChunk starting delete for: database.collection from { targetUid: -5985241970436000175 } -> { targetUid: -5981234632543141839 }

It seems the the cleaner goes through the whole hashed shard key range.
1. Is there a way to skip this cleanup with compaction, repair or full resync?

We also disabled "_secondaryThrottle" afterwards on the balancer setting, but it seems that this is not recognized on the replicaset

Tue Feb 18 06:07:23.792 [cleanupOldData-52f24e398cd98919080ca17b] Helpers::removeRangeUnlocked time spent waiting for replication: 1151188ms

2. Is there a way to disable it afterwards?