core/src/main/java/com/orientechnologies/orient/core/storage/impl/local/paginated/wal/OWALSegmentCache.java
public void sync() throws IOException {
    synchronized (lockObject) {
      if (segChannel != null) {
        lastAccessTime = System.nanoTime();
        flushBuffer();

        segChannel.force(false);
      }
    }
  }
public void sync() throws IOException {
    synchronized (lockObject) {
      if (segChannel != null) {
        lastAccessTime = System.nanoTime();
        flushBuffer();

        segChannel.force(false);
      }
    }
  }
Writes cache content to the file and performs <code>fsync</code>