diff --git a/test/random_access/src/test/java/seaewedfs/mmap/MmapFileTest.java b/test/random_access/src/test/java/seaweedfs/file/MmapFileTest.java
similarity index 98%
rename from test/random_access/src/test/java/seaewedfs/mmap/MmapFileTest.java
rename to test/random_access/src/test/java/seaweedfs/file/MmapFileTest.java
index e64fb85f0..1d741ee2f 100644
--- a/test/random_access/src/test/java/seaewedfs/mmap/MmapFileTest.java
+++ b/test/random_access/src/test/java/seaweedfs/file/MmapFileTest.java
@@ -1,4 +1,4 @@
-package seaewedfs.mmap;
+package seaweedfs.file;
 
 import org.junit.Test;
 
@@ -11,7 +11,7 @@ import java.nio.channels.FileChannel;
 
 public class MmapFileTest {
 
-    File dir = new File("/Users/chris/tmp/mm/dev");
+    static File dir = new File("/Users/chris/tmp/mm/dev");
 
     @Test
     public void testMmap() {
diff --git a/test/random_access/src/test/java/seaweedfs/file/RandomeAccessFileTest.java b/test/random_access/src/test/java/seaweedfs/file/RandomeAccessFileTest.java
new file mode 100644
index 000000000..cb5847567
--- /dev/null
+++ b/test/random_access/src/test/java/seaweedfs/file/RandomeAccessFileTest.java
@@ -0,0 +1,70 @@
+package seaweedfs.file;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.nio.ByteBuffer;
+import java.util.Random;
+
+public class RandomeAccessFileTest {
+
+    @Test
+    public void testRandomWriteAndRead() throws IOException {
+
+        File f = new File(MmapFileTest.dir, "mmap_file.txt");
+
+        RandomAccessFile af = new RandomAccessFile(f, "rw");
+        af.setLength(0);
+        af.close();
+
+        Random r = new Random();
+
+        int maxLength = 5000;
+
+        byte[] data = new byte[maxLength];
+        byte[] readData = new byte[maxLength];
+
+        for (int i = 4096; i < maxLength; i++) {
+
+            RandomAccessFile raf = new RandomAccessFile(f, "rw");
+            long fileSize = raf.length();
+
+            raf.readFully(readData, 0, (int)fileSize);
+
+            for (int x=0;x<fileSize;x++){
+                Assert.assertEquals(data[x], readData[x]);
+            }
+
+            int start = r.nextInt(i);
+            int stop = r.nextInt(i);
+            if (start > stop) {
+                int t = stop;
+                stop = start;
+                start = t;
+            }
+            if (stop > fileSize) {
+                fileSize = stop;
+                raf.setLength(fileSize);
+            }
+
+            randomize(r, data, start, stop);
+            raf.seek(start);
+            raf.write(data, start, stop-start);
+
+            raf.close();
+        }
+
+    }
+
+    private static void randomize(Random r, byte[] bytes, int start, int stop) {
+        for (int i = start; i < stop; i++) {
+            int rnd = r.nextInt();
+            bytes[i] = (byte) rnd;
+        }
+    }
+
+
+}