Converting data formats in a storage system: converting first data in a first format to second data in a second format, wherein second data in the second format includes a reference to the first data, wherein the first data and the second data are associated with a dataset, including updating the second data to include: a reference to first data associated with a portion of the dataset that precedes a data-converted portion of the dataset; second data associated with the data-converted portion of the dataset, wherein the second data associated with the data-converted portion of the dataset is in the second data format; and a reference to first data associated with a portion of the dataset that follows the data-converted portion of the dataset; and replacing first data associated with the data-converted portion of the dataset with a reference to the second data associated with the data-converted portion of the dataset.