Patent attributes
A new snapshot of a storage volume is created by instructing computing nodes to suppress write requests. Once pending write requests from the computing nodes are completed, 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. The snapshots may be represented by a storage manager in a hierarchy. Deleted snapshots may be flagged as such in the hierarchy and deletion may be implemented only in memory on a storage node, which is then restored from the hierarchy in the event of a crash. A snapshot is removed from the hierarchy when all segments previously are freed by garbage collection. A hybrid storage node may perform both computing and storage services. Data may be written with tags indicating encoding protocols used to encode the data.
