Reduction of journal log in a storage system

A non-transitory machine-readable medium storing instructions that upon execution cause a processor to:

• detect a trigger event for a reduction operation of a journal log, wherein the journal log records writes to a storage volume;
• in response to a detection of the trigger event, select a set of target segments in the journal log, wherein the set of target segments comprise a plurality of journal entries;
• determine a set of storage locations that were modified by write operations recorded in the plurality of journal entries of the set of target segments;
• identify a first subset of journal entries in the set of target segments, wherein each journal entry of the first subset of journal entries records a most recent write operation performed to a different storage location of the set of storage locations, wherein each journal entry of the first subset of journal entries records a set of data blocks written to the different storage location of the set of storage locations, and wherein the set of target segments includes a second subset of journal entries that are excluded from the first subset of journal entries;
• generate a new segment that includes the first subset of journal entries and excludes the second subset of journal entries of the set of target segments;
• and
• replace, in the journal log, the set of target segments with the generated new segment that includes the first subset of journal entries and excludes the second subset of journal entries of the set of target segments.

A method comprising:

• detecting, by a controller, a trigger event for a reduction operation of a journal log, wherein the journal log records writes to a storage volume;
• in response to a detection of the trigger event, selecting, by the controller, a set of target segments in the journal log, wherein the set of target segments comprise a plurality of journal entries;
• determining, by the controller, a set of storage locations that were modified by write operations recorded in the plurality of journal entries of the set of target segments;
• identifying, by the controller, a first subset of journal entries in the set of target segments, wherein each journal entry of the first subset of journal entries records a most recent write operation performed to a different storage location of the set of storage locations, wherein each journal entry of the first subset of journal entries records a set of data blocks written to the different storage location of the set of storage locations, and wherein the set of target segments includes a second subset of journal entries that are excluded from the first subset of journal entries;
• generating, by the controller, a new segment that includes the first subset of journal entries and excludes the second subset of journal entries of the set of target segments;
• and
• replacing in the journal log, by the controller, the set of target segments with the generated new segment that includes the first subset of journal entries and excludes the second subset of journal entries of the set of target segments.