The property "dfs.name.dir" allows you to control where Hadoop writes
NameNode metadata.
You should have a property like
<property>
<name>dfs.name.dir</name>
<value>/data/zhang/hadoop/name/data</value>
</property>
to make sure the NameNode data isn't being deleted when you delete the
files in /tmp.
-Matt
On Jun 26, 2009, at 2:33 PM, Boyu Zhang wrote:
Matt,
Thanks a lot for your reply! I did formatted the namenode. But I got
the
same error again. And actually I successfully run the example jar
file once,
but after that one time, I couldn't get it run again. I clean the /
tmp dir
every time before I format namenode again(I am just testing it, so I
don't
worry about losing data:). Still, I got the same error when I
execute the
bin/start-dfs.sh . I checked my conf, and I can't figure out why.
Here is my
conf file:
I really appreciate if you could take a look at it. Thanks a lot.
<configuration>
<property>
<name>fs.default.name</name>
<value>hdfs://hostname1:9000</value>
</property>
<property>
<name>mapred.job.tracker</name>
<value>hostname2:9001</value>
</property>
<property>
<name>dfs.data.dir</name>
<value>/data/zhang/hadoop/dfs/data</value>
<description>Determines where on the local filesystem an DFS data
node
should store its blocks. If this is a comma-delimited
list of directories, then data will be stored in all named
directories, typically on different devices.
Directories that do not exist are ignored.
</description>
</property>
<property>
<name>mapred.local.dir</name>
<value>/data/zhang/hadoop/mapred/local</value>
<description>The local directory where MapReduce stores intermediate
data files. May be a comma-separated list of
directories on different devices in order to spread disk i/o.
Directories that do not exist are ignored.
</description>
</property>
</configuration>
-----Original Message-----
From: Matt Massie [mailto:m...@cloudera.com]
Sent: Friday, June 26, 2009 4:31 PM
To: core-user@hadoop.apache.org
Subject: Re: Error in Cluster Startup: NameNode is not formatted
Boyu-
You didn't do anything stupid. I've forgotten to format a NameNode
too myself.
If you check the QuickStart guide at
http://hadoop.apache.org/core/docs/current/quickstart.html
you'll see that formatting the NameNode is the first of the
Execution section (near the bottom of the page).
The command to format the NameNode is:
hadoop namenode -format
A warning though, you should only format your NameNode once. Just
like formatting any filesystem, you can loss data if you (re)format.
Good luck.
-Matt
On Jun 26, 2009, at 1:25 PM, Boyu Zhang wrote:
Hi all,
I am a student and I am trying to install the Hadoop on a cluster, I
have
one machine running namenode, one running jobtracker, two slaves.
When I run the /bin/start-dfs.sh , there is something wrong with my
namenode, it won't start. Here is the error message in the log file:
ERROR org.apache.hadoop.fs.FSNamesystem: FSNamesystem initialization
failed.
java.io.IOException: NameNode is not formatted.
at
org.apache.hadoop.dfs.FSImage.recoverTransitionRead(FSImage.java:243)
at
org.apache.hadoop.dfs.FSDirectory.loadFSImage(FSDirectory.java:80)
at
org.apache.hadoop.dfs.FSNamesystem.initialize(FSNamesystem.java:294)
at
org.apache.hadoop.dfs.FSNamesystem.<init>(FSNamesystem.java:273)
at org.apache.hadoop.dfs.NameNode.initialize(NameNode.java:148)
at org.apache.hadoop.dfs.NameNode.<init>(NameNode.java:193)
at org.apache.hadoop.dfs.NameNode.<init>(NameNode.java:179)
at
org.apache.hadoop.dfs.NameNode.createNameNode(NameNode.java:830)
at org.apache.hadoop.dfs.NameNode.main(NameNode.java:839)
I think it is something stupid i did, could somebody help me out?
Thanks a
lot!
Sincerely,
Boyu Zhang
