private void setMaxCrfDrfSize() {
    int crfPct = Integer.getInteger(GeodeGlossary.GEMFIRE_PREFIX + "CRF_MAX_PERCENTAGE", 90);
    if (crfPct > 100 || crfPct < 0) {
      crfPct = 90;
    }
    maxCrfSize = (long) (maxOplogSize * (crfPct / 100.0));
    maxDrfSize = maxOplogSize - maxCrfSize;
  }
There're 3 cases to use writeRVV: 1) endGII: DiskRegion.writeRVV(region=null, true),
Oplog.writeRVV(true,null) 2) beginGII: DiskRegion.writeRVV(region=this, false),
Oplog.writeRVV(false,sourceRVV!=null) 3) clear: DiskRegion.writeRVV(region=this, null),
Oplog.writeRVV(null,sourceRVV!=null)
geode-core/src/main/java/org/apache/geode/internal/cache/Oplog.java