A new snapshot of a storage volume is created by instructing computing nodes to suppress write requests. Storage nodes create a new snapshot for the storage volume by allocating a new segment to the new snapshot and finalizes and performs garbage collection with respect to segments allocated to the previous snapshot. Subsequent write requests to the storage volume are then performed on the segments allocated to the new snapshot. A segment maps segments to a particular snapshot and metadata stored in the segment indicates storage volume addresses of data written to the segment. The snapshots may be represented by a storage manager in a hierarchy that identifies an ordering of snapshots and branches to clone snapshots. A non-snapshot volume may be converted to a snapshot volume at any point after creation.