Erratum : dfs.namenode.name.dir is not unique, it can be a
comma-separated list in order to have more than one dir containing the
fsimage, preferably with one pointing to an NFS mount or at least on
different physical disks.
Sorry about that
Anyway, having more than one dir won't create a standby node, you need
to configure HA
Ulul
Le 18/02/2015 21:14, Ulul a écrit :
Hi
This is not your hadoop version but your java version you displayed
For hadoop version remove the dash : hdfs version
The dfs.namenode.name.dir is the dir for the namenode process to store
the filesystem image. It is unique.
What you seem to be looking for is Namenode HA, how to install a
standby NN (and not a secondary NN which is the poorly named process
that merges FS changes into the fs image).
This exists in Hadoop v2.x
You can find doc there :
https://hadoop.apache.org/docs/current/hadoop-project-dist/hadoop-hdfs/HDFSHighAvailabilityWithQJM.html
Since you seem to already have a running cluster here is a blog post
about configuring HA on an existing cluster (I didn't try it) :
http://johnjianfang.blogspot.fr/2014/09/how-to-configure-hadoop-ha-for-running.html
But you need to test thoroughly on a test environment before doing
anything on a cluster holding production data
Cheers
Ulul
Le 18/02/2015 10:50, Mich Talebzadeh a écrit :
Hi,
I have a Hadoop instance (single node) installed on RHES5 running OK.
The version of Hadoop is
hdfs -version
java version "1.7.0_25"
Java(TM) SE Runtime Environment (build 1.7.0_25-b15)
Java HotSpot(TM) 64-Bit Server VM (build 23.25-b01, mixed mode)
I would like to add another file to namenode in hdfs-site.xml. That
is effectively building resiliency and multi-plexing it.
The new file will be on Solid State Disk. I tried adding it to
hdfs-site.xml file by having
<property>
<name>dfs.namenode.name.dir</name>
<value>file:/work/hadoop/hadoop_store/hdfs/namenode</value>
</property>
And changing it to
<property>
<name>dfs.namenode.name.dir</name>
<value>file:/work/hadoop/hadoop_store/hdfs/namenode</value>
*<value>file:/ssddata6/hadoop/hadoop_store/hdfs/namenode</value>*
</property>
But it does not work!
Any ideas if one can add the secondary namenode file without losing
data etc?
Thanks
Mich Talebzadeh
http://talebzadehmich.wordpress.com
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