I've had to reindex some data in order to change the shard count on the index they were in: I went from having one shard on the old index to four shards on the new index. The old index (1 shard) was 38.1GB; the new index (4 shards) is 46.7GB; both index have the same number of documents. Is there any reason why just going from one shard to four would cause such a large increase in size (I did expect some per-shard overhead)? Both indices have are using the same template and field mappings.
This is on ES 2.0.