US 11,755,416 B2
Storage tiering for backup data
Milind Borate, Pune (IN); Somesh Jain, Pune (IN); Pallavi Thakur, Pune (IN); and Anand Apte, Pune (IN)
Assigned to Druva Inc., Santa Clara, CA (US)
Filed by Druva Inc., Santa Clara, CA (US)
Filed on Jan. 8, 2021, as Appl. No. 17/145,147.
Claims priority of application No. 202041001695 (IN), filed on Jan. 14, 2020; and application No. 202041051738 (IN), filed on Nov. 27, 2020.
Prior Publication US 2021/0216407 A1, Jul. 15, 2021
Int. Cl. G06F 11/14 (2006.01)
CPC G06F 11/1448 (2013.01) 22 Claims
OG exemplary drawing
 
1. A computer-implemented method of migrating data from a warm-tier data store to a cold-tier data store, the computer-implemented method comprising:
determining that one or more originally warm snapshots have transitioned to one or more cold snapshots;
identifying that a plurality of data blocks stored in the warm-tier data store are ready to be transferred to the cold-tier data store due to the one or more originally warm snapshots having transitioned to the one or more cold snapshots, the plurality of data blocks being referenced by the one or more originally warm snapshots, wherein identifying that the plurality of data blocks stored in the warm-tier data store are ready to be transferred to the cold-tier data store comprises:
determining, for a particular data block, a total reference count of the particular data block,
determining, for the particular data block, a cold reference count of the particular data block,
incrementing the cold reference count for each of the originally warm snapshots that reference the particular data block having transitioned to a cold snapshot, and
determining that the particular data block is ready to be transferred to the cold-tier data store responsive to the cold reference count being equal to the total reference count;
grouping a subset of data blocks of the plurality of data blocks based on retention periods or expected restoration of the data blocks in the subset; and
transmitting the subset of data blocks as a unit to the cold-tier data store for storage.