@Override
  protected final void postSetUp() throws Exception {
    diskProps.setDiskDirs(dirs);
    diskProps.setPersistBackup(true);
    region = DiskRegionHelperFactory.getSyncPersistOnlyRegion(cache, diskProps, Scope.LOCAL);

    log = ds.getLogWriter();
  }
Disk region perf test for Persist only with sync writes.
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/diskPerf/DiskRegionPersistOnlySyncJUnitTest.java