1. A method comprising: receiving a first incremental mirror data set that reflects a backup data set for a plurality of time-ordered journal entries generated by incrementally backing up a dynamic source file, with the first incremental mirror data set including all journal entries up to, but not including a first corrupted journal entry, which is the earliest in time journal entry, of the plurality of journal entries, which is corrupted; receiving a determination that the first incremental mirror data set is a most up to date set which: (i) is uncorrupted, and (ii) can be constructed from the backup data set and the plurality of time-ordered journal entries; and replacing the source file data set with the first incremental mirror data set.