Dense tree volume metadata update logging and checkpointing

摘要

The embodiments described herein are directed to efficient logging and checkpointing of metadata managed by a volume layer of a storage input/output (I/O) stack executing on one or more nodes of a cluster. The metadata managed by the volume layer, i.e., the volume metadata, is illustratively organized as a multi-level dense tree metadata structure, wherein each level of the dense tree metadata structure (dense tree) includes volume metadata entries for storing the volume metadata. Each volume metadata entry may be a descriptor that embodies one of a plurality of types, including a data entry and an index entry, and a hole (i.e., absence of data) entry.

主权项

1. A method comprising:
receiving a write request directed towards a logical unit (LUN), the write request having data, a logical block address (LBA) and a first length representing a first address range of the LUN, the write request processed at a storage system having a memory; associating a key with the data; storing the key in a first data entry of a metadata structure, the first data entry having a first offset and the first length representing the first address range of the LUN, the metadata structure having a predetermined offset and a predetermined length representing a second address range of the LUN which extends over a greater number of addresses than the first address range; merging the first data entry of the metadata structure with a second data entry of the metadata structure to form a third data entry, the second data entry having a second offset and a second length representing a third address range of the LUN, the third data entry having a third offset and a third length representing a merger of the first address range and the third address range; and storing the third data entry in a storage array of solid state drives (SSDs) attached to the storage system.