What is the o/p of command hdfs dfsadmin -upgradeProgress status
If it says upgrade is complete then you can do some sanity check by hdfs fsck. Stop the servers by stop-dfs.sh and then rollback by command start-dfs.sh -rollback On 9/18/14, sam liu <samliuhad...@gmail.com> wrote: > 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) >> > >> >
