US 12,277,338 B1
Systems and methods of updating sparse metadata in metadata delta log (MDL)-based storage clusters
Seman Shen, Shanghai (CN); and Vladimir Shveidel, Pardes Hana-Karkur (IL)
Assigned to Dell Products L.P., Round Rock, TX (US)
Filed by Dell Products L.P., Round Rock, TX (US)
Filed on Dec. 6, 2023, as Appl. No. 18/530,668.
Int. Cl. G06F 3/06 (2006.01)
CPC G06F 3/065 (2013.01) [G06F 3/0604 (2013.01); G06F 3/0679 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
providing a 3-level metadata delta log (MDL) including a first level for a first set of logical data containers designated as an “active” set, a second level for a second set of logical data containers designated as a “de-staging” set, and a third level for a third set of logical data containers designated as a “base” set, the base set of logical data containers containing a base set of space accounting (SA) statistics pertaining to logical and/or physical storage space used by storage objects on a storage system, the SA statistics being associated with sparse SA identifier (SA-ID) values;
receiving delta updates of the SA statistics at the active set of logical data containers;
once one, some, or all of the active set of logical data containers are full, switching the “active” and “de-staging” designations of the first and second sets of logical data containers, respectively;
merging, logical data container-by-logical data container, at least some of the delta updates of SA statistics contained in the de-staging set with the base set of SA statistics to obtain first merged SA statistics; and
reading at least some of the first merged SA statistics.