Thanks for your comment! I can upgrade from 2.2.0 to 2.4.1 using command 'start-dfs.sh -upgrade', however failed to rollback from 2.4.1 to 2.2.0 using command 'start-dfs.sh -rollback': the namenode always stays on safe mode(awaiting reported blocks (0/315)).
Why? 2014-09-18 1:51 GMT-07:00 Susheel Kumar Gadalay <skgada...@gmail.com>: > You have to upgrade both name node and data node. > > Better issue start-dfs.sh -upgrade. > > Check whether current and previous directories are present in both > dfs.namenode.name.dir and dfs.datanode.data.dir directory. > > On 9/18/14, sam liu <samliuhad...@gmail.com> wrote: > > Hi Expert, > > > > Below are my steps and is it a hadoop bug or did I miss any thing? > Thanks! > > > > Step: > > [A] Upgrade > > 1. Install Hadoop 2.2.0 cluster > > 2. Stop Hadoop services > > 3. Replace 2.2.0 binaries with 2.4.1 binaries > > 4. Start datanodes: $HADOOP_HOME/sbin/hadoop-daemon.sh start datanode > > 5. Start namenode with option upgrade: $HADOOP_HOME/sbin/hadoop-daemon.sh > > start namenode -upgrade > > 6. Start secondary namenode, tasktracker and jobtracker > > > > Result: > > > > Whole upgrade process could be completed successfully. > > > > [B] Rollback > > 1. Stop all hadoop services > > 2. Replace 2.4.1 binaries with 2.2.0 binaries > > 3. Start datanodes: $HADOOP_HOME/sbin/hadoop-daemon.sh start datanode > > 4. Start namenode with option upgrade: $HADOOP_HOME/sbin/hadoop-daemon.sh > > start namenode -rollback > > > > Result: > > > > Namenode service could be started > > Datanodes failed with exception: > > Issue: DataNode failed with following exception > > 2014-09-17 11:04:51,416 INFO > > org.apache.hadoop.hdfs.server.common.Storage: Lock on > > /hadoop/hdfs/data/in_use.lock acquired by nodename 817443@shihc071-public > > 2014-09-17 11:04:51,418 FATAL > > org.apache.hadoop.hdfs.server.datanode.DataNode: Initialization failed > for > > block pool Block pool BP-977402492-9.181.64.185-1410497086460 (storage > id ) > > service to hostname/ip:9000 > > org.apache.hadoop.hdfs.server.common.IncorrectVersionException: > > Unexpected version of storage directory /hadoop/hdfs/data. Reported: -55. > > Expecting = -47. > > at > > > org.apache.hadoop.hdfs.server.common.Storage.setLayoutVersion(Storage.java:1082) > > at > > > org.apache.hadoop.hdfs.server.datanode.DataStorage.setFieldsFromProperties(DataStorage.java:302) > > at > > > org.apache.hadoop.hdfs.server.common.Storage.readProperties(Storage.java:921) > > >
