1. A method comprising: identifying a source physical storage location in a file system that supports simultaneous access by multiple independent processes; identifying a target physical storage location in the file system; migrating contents of the source physical storage location to the target physical storage location, the migrating comprising: disallowing new allocations to the source physical storage location; copying contents from the source physical storage location to the target physical storage location; receiving a write request to write data to the source physical storage location, the receiving prior to or during the migrating; servicing the write request contemporaneously with the migrating; and redirecting, responsive to the migrating completing, read and write requests directed to the source physical storage location to the target physical storage location, the requests from the multiple independent processes and comprising both logical input/outputs (I/Os) and physical I/Os.