diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 2966450a798..4b66a8091c0 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -70,6 +70,8 @@ Release 2.0.0 - UNRELEASED
 
     HDFS-3167. CLI-based driver for MiniDFSCluster. (Henry Robinson via atm)
 
+    HDFS-3120. Enable hsync and hflush by default. (eli)
+
   IMPROVEMENTS
 
     HDFS-2018. Move all journal stream management code into one place.
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
index b34dcf7a6b0..46c7b079ed4 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
@@ -300,8 +300,8 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
   NameNodeResourceChecker nnResourceChecker;
 
   private FsServerDefaults serverDefaults;
-  // allow appending to hdfs files
-  private boolean supportAppends = true;
+
+  private boolean supportAppends;
   private ReplaceDatanodeOnFailure dtpReplaceDatanodeOnFailure = 
       ReplaceDatanodeOnFailure.DEFAULT;
 
@@ -1812,9 +1812,10 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
       throws AccessControlException, SafeModeException,
       FileAlreadyExistsException, FileNotFoundException,
       ParentNotDirectoryException, IOException {
-    if (supportAppends == false) {
-      throw new UnsupportedOperationException("Append to hdfs not supported." +
-                            " Please refer to dfs.support.append configuration parameter.");
+    if (!supportAppends) {
+      throw new UnsupportedOperationException(
+          "Append is not enabled on this NameNode. Use the " +
+          DFS_SUPPORT_APPEND_KEY + " configuration option to enable it.");
     }
     LocatedBlock lb = null;
     writeLock();
@@ -2894,9 +2895,8 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
 
         //remove lease, close file
         finalizeINodeFileUnderConstruction(src, pendingFile);
-      } else if (supportAppends) {
+      } else {
         // If this commit does not want to close the file, persist blocks
-        // only if append is supported or we're explicitly told to
         dir.persistBlocks(src, pendingFile);
       }
     } finally {
@@ -4479,9 +4479,7 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
     } finally {
       writeUnlock();
     }
-    if (supportAppends || persistBlocks) {
-      getEditLog().logSync();
-    }
+    getEditLog().logSync();
     LOG.info("updatePipeline(" + oldBlock + ") successfully to " + newBlock);
   }
 
@@ -4520,11 +4518,8 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
     }
     blockinfo.setExpectedLocations(descriptors);
 
-    // persist blocks only if append is supported
     String src = leaseManager.findPath(pendingFile);
-    if (supportAppends) {
-      dir.persistBlocks(src, pendingFile);
-    }
+    dir.persistBlocks(src, pendingFile);
   }
 
   // rename was successful. If any part of the renamed subtree had
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml b/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml
index b9391449f1e..2ab7c1dec8f 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml
@@ -836,4 +836,12 @@
   </description>
 </property>
 
+<property>
+  <name>dfs.support.append</name>
+  <value>true</value>
+  <description>
+    Does HDFS allow appends to files?
+  </description>
+</property>
+
 </configuration>
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/aop/org/apache/hadoop/hdfs/TestFiPipelines.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/aop/org/apache/hadoop/hdfs/TestFiPipelines.java
index 61ab20061fc..ddeb57d3ff3 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/aop/org/apache/hadoop/hdfs/TestFiPipelines.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/aop/org/apache/hadoop/hdfs/TestFiPipelines.java
@@ -230,7 +230,6 @@ public class TestFiPipelines {
     conf.setInt(DFSConfigKeys.DFS_BYTES_PER_CHECKSUM_KEY, customPerChecksumSize);
     conf.setInt(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, customBlockSize);
     conf.setInt(DFSConfigKeys.DFS_CLIENT_WRITE_PACKET_SIZE_KEY, customBlockSize / 2);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
     conf.setInt(DFSConfigKeys.DFS_CLIENT_SOCKET_TIMEOUT_KEY, 0);
   }
 
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/permission/TestStickyBit.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/permission/TestStickyBit.java
index 593134350d7..ca4862bd010 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/permission/TestStickyBit.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/permission/TestStickyBit.java
@@ -163,7 +163,6 @@ public class TestStickyBit extends TestCase {
     try {
       Configuration conf = new HdfsConfiguration();
       conf.setBoolean(DFSConfigKeys.DFS_PERMISSIONS_ENABLED_KEY, true);
-      conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
       cluster = new MiniDFSCluster.Builder(conf).numDataNodes(4).build();
 
       FileSystem hdfs = cluster.getFileSystem();
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/FileAppendTest4.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/FileAppendTest4.java
index d837c0f71af..d26e2cb4e2c 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/FileAppendTest4.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/FileAppendTest4.java
@@ -55,7 +55,6 @@ public class FileAppendTest4 {
     conf.setInt(DFSConfigKeys.DFS_BYTES_PER_CHECKSUM_KEY, BYTES_PER_CHECKSUM);
     conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, BLOCK_SIZE);
     conf.setInt(DFSConfigKeys.DFS_CLIENT_WRITE_PACKET_SIZE_KEY, PACKET_SIZE);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
   }
   
   @BeforeClass
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestClientProtocolForPipelineRecovery.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestClientProtocolForPipelineRecovery.java
index 259d26a3049..a0b7b0d151c 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestClientProtocolForPipelineRecovery.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestClientProtocolForPipelineRecovery.java
@@ -40,7 +40,6 @@ public class TestClientProtocolForPipelineRecovery {
   @Test public void testGetNewStamp() throws IOException {
     int numDataNodes = 1;
     Configuration conf = new HdfsConfiguration();
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
     MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).numDataNodes(numDataNodes).build();
     try {
       cluster.waitActive();
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDataTransferProtocol.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDataTransferProtocol.java
index 71ad9afa950..3ef892b4f19 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDataTransferProtocol.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDataTransferProtocol.java
@@ -207,7 +207,6 @@ public class TestDataTransferProtocol extends TestCase {
   @Test public void testOpWrite() throws IOException {
     int numDataNodes = 1;
     Configuration conf = new HdfsConfiguration();
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
     MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).numDataNodes(numDataNodes).build();
     try {
       cluster.waitActive();
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileAppend2.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileAppend2.java
index 3b116d4940c..0b59086dae8 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileAppend2.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileAppend2.java
@@ -85,7 +85,6 @@ public class TestFileAppend2 extends TestCase {
       SimulatedFSDataset.setFactory(conf);
     }
     conf.setInt(DFSConfigKeys.DFS_DATANODE_HANDLER_COUNT_KEY, 50);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
     fileContents = AppendTestUtil.initBuffer(AppendTestUtil.FILE_SIZE);
     MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
     FileSystem fs = cluster.getFileSystem();
@@ -338,7 +337,6 @@ public class TestFileAppend2 extends TestCase {
     conf.setInt(DFSConfigKeys.DFS_CLIENT_SOCKET_TIMEOUT_KEY, 30000);
     conf.setInt(DFSConfigKeys.DFS_DATANODE_SOCKET_WRITE_TIMEOUT_KEY, 30000);
     conf.setInt(DFSConfigKeys.DFS_DATANODE_HANDLER_COUNT_KEY, 50);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
 
     MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
                                                .numDataNodes(numDatanodes)
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileAppend3.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileAppend3.java
index aedbac30ac2..40c0a1a3ed4 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileAppend3.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileAppend3.java
@@ -70,7 +70,6 @@ public class TestFileAppend3 extends junit.framework.TestCase {
         AppendTestUtil.LOG.info("setUp()");
         conf = new HdfsConfiguration();
         conf.setInt(DFSConfigKeys.DFS_BYTES_PER_CHECKSUM_KEY, 512);
-        conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
         buffersize = conf.getInt(CommonConfigurationKeys.IO_FILE_BUFFER_SIZE_KEY, 4096);
         cluster = new MiniDFSCluster.Builder(conf).numDataNodes(DATANODE_NUM).build();
         fs = (DistributedFileSystem)cluster.getFileSystem();
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileAppend4.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileAppend4.java
index ab60c4c2210..f35bc465ed3 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileAppend4.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileAppend4.java
@@ -79,7 +79,6 @@ public class TestFileAppend4 {
     if (simulatedStorage) {
       SimulatedFSDataset.setFactory(conf);
     }
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
 
     // lower heartbeat interval for fast recognition of DN death
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_KEY,
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileConcurrentReader.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileConcurrentReader.java
index 88d5d4bc2f6..632d8cc35e3 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileConcurrentReader.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileConcurrentReader.java
@@ -311,7 +311,6 @@ public class TestFileConcurrentReader extends junit.framework.TestCase {
     final int writeSize,
     Configuration conf
   ) throws IOException {
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, syncType == SyncType.APPEND);
     conf.setBoolean(DFSConfigKeys.DFS_DATANODE_TRANSFERTO_ALLOWED_KEY,
         transferToAllowed);
     init(conf);
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileCreationDelete.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileCreationDelete.java
index 379e83d9191..6517391885d 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileCreationDelete.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileCreationDelete.java
@@ -43,7 +43,6 @@ public class TestFileCreationDelete extends junit.framework.TestCase {
     conf.setInt("ipc.client.connection.maxidletime", MAX_IDLE_TIME);
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_KEY, 1000);
     conf.setInt(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY, 1);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
 
     // create cluster
     MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestLeaseRecovery.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestLeaseRecovery.java
index f68b3c3bd95..98b8bdf5924 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestLeaseRecovery.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestLeaseRecovery.java
@@ -70,7 +70,6 @@ public class TestLeaseRecovery extends junit.framework.TestCase {
     final int ORG_FILE_SIZE = 3000; 
     Configuration conf = new HdfsConfiguration();
     conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, BLOCK_SIZE);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
     MiniDFSCluster cluster = null;
 
     try {
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestPipelines.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestPipelines.java
index 0d2ebc96af6..2c813a9582a 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestPipelines.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestPipelines.java
@@ -155,7 +155,6 @@ public class TestPipelines {
     conf.setInt(DFSConfigKeys.DFS_BYTES_PER_CHECKSUM_KEY, customPerChecksumSize);
     conf.setInt(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, customBlockSize);
     conf.setInt(DFSConfigKeys.DFS_CLIENT_WRITE_PACKET_SIZE_KEY, customBlockSize / 2);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
     conf.setInt(DFSConfigKeys.DFS_CLIENT_SOCKET_TIMEOUT_KEY, 0);
   }
 
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestQuota.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestQuota.java
index 72e140726c7..14444137445 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestQuota.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestQuota.java
@@ -82,7 +82,6 @@ public class TestQuota {
     // Space quotas
     final int DEFAULT_BLOCK_SIZE = 512;
     conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, DEFAULT_BLOCK_SIZE);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
     final MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).numDataNodes(2).build();
     final FileSystem fs = cluster.getFileSystem();
     assertTrue("Not a HDFS: "+fs.getUri(),
@@ -531,7 +530,6 @@ public class TestQuota {
     // set a smaller block size so that we can test with smaller 
     // diskspace quotas
     conf.set(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, "512");
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
     final MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).numDataNodes(2).build();
     final FileSystem fs = cluster.getFileSystem();
     assertTrue("Not a HDFS: "+fs.getUri(),
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestReadWhileWriting.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestReadWhileWriting.java
index 2bf6cbba3e3..23e6a414f55 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestReadWhileWriting.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestReadWhileWriting.java
@@ -56,8 +56,6 @@ public class TestReadWhileWriting {
   @Test
   public void pipeline_02_03() throws Exception {
     final Configuration conf = new HdfsConfiguration();
-    //enable append
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
     conf.setLong(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY, 1);
 
     // create cluster
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestRenameWhileOpen.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestRenameWhileOpen.java
index 5882f1a5a10..6189a96f81c 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestRenameWhileOpen.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestRenameWhileOpen.java
@@ -54,7 +54,6 @@ public class TestRenameWhileOpen extends junit.framework.TestCase {
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_KEY, 1000);
     conf.setInt(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY, 1);
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_SAFEMODE_THRESHOLD_PCT_KEY, 1);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
 
     // create cluster
     System.out.println("Test 1*****************************");
@@ -140,7 +139,6 @@ public class TestRenameWhileOpen extends junit.framework.TestCase {
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_KEY, 1000);
     conf.setInt(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY, 1);
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_SAFEMODE_THRESHOLD_PCT_KEY, 1);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
     System.out.println("Test 2************************************");
 
     // create cluster
@@ -215,7 +213,6 @@ public class TestRenameWhileOpen extends junit.framework.TestCase {
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_KEY, 1000);
     conf.setInt(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY, 1);
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_SAFEMODE_THRESHOLD_PCT_KEY, 1);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
     System.out.println("Test 3************************************");
 
     // create cluster
@@ -280,7 +277,6 @@ public class TestRenameWhileOpen extends junit.framework.TestCase {
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_KEY, 1000);
     conf.setInt(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY, 1);
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_SAFEMODE_THRESHOLD_PCT_KEY, 1);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
     System.out.println("Test 4************************************");
 
     // create cluster
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlockTokenWithDFS.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlockTokenWithDFS.java
index c9436e4f332..687e813e25c 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlockTokenWithDFS.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlockTokenWithDFS.java
@@ -182,8 +182,6 @@ public class TestBlockTokenWithDFS {
     conf.setInt(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY, 1);
     conf.setInt(DFSConfigKeys.DFS_REPLICATION_KEY, numDataNodes);
     conf.setInt("ipc.client.connect.max.retries", 0);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY,
-        DFSConfigKeys.DFS_SUPPORT_APPEND_DEFAULT);
     return conf;
   }
 
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/TestDatanodeRestart.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/TestDatanodeRestart.java
index 594a66ba72a..773864e2f3c 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/TestDatanodeRestart.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/TestDatanodeRestart.java
@@ -76,7 +76,6 @@ public class TestDatanodeRestart {
     Configuration conf = new HdfsConfiguration();
     conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, 1024L);
     conf.setInt(DFSConfigKeys.DFS_CLIENT_WRITE_PACKET_SIZE_KEY, 512);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
     MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).numDataNodes(2).build();
     cluster.waitActive();
     try {
@@ -141,7 +140,6 @@ public class TestDatanodeRestart {
     Configuration conf = new HdfsConfiguration();
     conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, 1024L);
     conf.setInt(DFSConfigKeys.DFS_CLIENT_WRITE_PACKET_SIZE_KEY, 512);
-    conf.setBoolean(DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, true);
     MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
     cluster.waitActive();
     try {