Garbage-collection in Log-based Block Devices with Snapshots

A method for garbage-collection includes obtaining a request to compact a plurality of log files of a log-structured volume. Each log file includes fresh block runs in use and stale block runs no longer in use. The log-structured volume includes a plurality of snapshots. For each respective snapshot, the method includes determining, using a plurality of interval maps, the fresh block runs of the plurality of log files used by the respective snapshot. For each respective log file, the method includes writing the fresh block runs of the respective log file to a respective compacted log file and generating a respective per-log diff file. The method includes, for each respective snapshot, generating a respective checkpoint based on respective per-log diff files and deleting each respective log file of the plurality of log files.