1. A data storage system, comprising: a first storage device of a first storage device type; a second storage device of a second storage device type; and a processor configured to implement a hybrid file system configured to store each of a plurality of data values in at least a corresponding primary location, which for a given data value may be in at least one of the first storage device or the second storage device; wherein the hybrid file system is configured to use a first access approach optimized based on a first access attribute of the first storage device type to interact with the first storage device and a second access approach optimized based on a second access attribute of the second storage device type to interact with the second storage device, wherein data comprising a set of one or more blocks of a first size associated with the first storage device is configured to be written back to the second storage device, wherein the set of one or more blocks of the first size associated with the first storage device to be written back corresponds to a second size of a block associated with the second storage device.