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Date: Thu, 18 Sep 2014 16:45:00 +0530
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Subject: Re: Failed to rollback from hadoop-2.4.1 to hadoop 2.2.0
From: Susheel Kumar Gadalay <skgadalay@gmail.com>
To: user@hadoop.apache.org
Content-Type: text/plain; charset=UTF-8

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 <samliuhadoop@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 <skgadalay@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 <samliuhadoop@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)
>> >
>>
>