1. A method to perform file system migration, the method comprising: associating a source block device to a destination block device, wherein the source block device and the destination block device include a plurality of source blocks and destination blocks, respectively; directing at least one command for a source block from the plurality of source blocks to the source block device or the destination block device based at least on the associating; and updating a destination block from the plurality of destination blocks based, in part, on the at least one directed command.