public static String getKRFFilenameFromCRFFilename(String crfFilename) {
    return crfFilename.substring(0, crfFilename.length() - Oplog.CRF_FILE_EXT.length())
        + Oplog.KRF_FILE_EXT;
  }
Copy any live entries last stored in this oplog to the current oplog. No need to copy deletes
in the drf. Backup only needs them until all the older crfs are empty.
geode-core/src/main/java/org/apache/geode/internal/cache/Oplog.java