| 44 | |
| 45 | * Right now, our NameNode is in SAFE mode waiting for the DataNodes to connect. |
| 46 | |
| 47 | * Start the rest of HDFS |
| 48 | |
| 49 | When the datanodes start, they will connect to the Name Node and an upgrade will be initiated. |
| 50 | |
| 51 | {{{ |
| 52 | .... hadoop-dfs start |
| 53 | }}} |
| 54 | |
| 55 | |
| 56 | Once all the DataNodes have upgraded, you should see a message that Safe mode will be turned off automatically in X seconds. |
| 57 | |
| 58 | * start MapReduce |
| 59 | After you have verified correct operation of HDFS, you are ready to start MapReduce. |
| 60 | |
| 61 | * finalize the hdfs upgrade |
| 62 | |
| 63 | Now that you've confirmed your cluster is successfully running on Hadoop 0.20, you can go ahead and finalize the HDFS upgrade: |
| 64 | {{{{ |
| 65 | $ sudo -u hadoop hadoop dfsadmin -finalizeUpgrade |
| 66 | }}} |