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HDFS Forum

Namenode not starting (6x EC2 micro instance)

  • #42422


    I installed a 6 node cluster on EC2 micro instances, based on this guide:

    Yes, the guide recommends to use medium and large (for NN) instances.
    As this is just a proof of concept install I thought to try it out on micro instances.
    If this is the simple reason for the problem I am happy to go with a larger instance.

    Everything worked fine so far until service startup, where the namenode is constantly failing.
    A link to the namenode log:

    Any feedback would be very much appreciated!



  • Author
  • #42435
    Robert Molina

    Hi Manuel,
    What version of HDP did you install? What is the OS you installed on EC2 to host hadoop? Can you start the service manually by executing the following:

    su – hdfs -c ‘/usr/lib/hadoop/bin/ start namenode’


    Chris Nauroth

    Hi Manuel,

    I expect that an EC2 micro instance won’t work, at least for the NameNode. Micro instances only have 0.6 GB of RAM. The NameNode generally needs a lot more RAM than that. I believe Ambari configures the NameNode heap size to 1 GB by default, which might explain why the process fails to start.

    Hope this helps,


    Hi Robert, hi Chris,

    many thanks for the fast reply!

    When starting the namenode via the console:

    [root@ambarimaster bin]# su -l hdfs -c “/usr/lib/hadoop/bin/ –config /etc/hadoop/conf start namenode”
    starting namenode, logging to /var/log/hadoop/hdfs/hadoop-hdfs-namenode-ambarimaster.hdp.hadoop.out
    Java HotSpot(TM) 64-Bit Server VM warning: MaxNewSize (655360k) is equal to or greater than the entire heap (262144k). A new generation size of 262080k will be used.
    Error occurred during initialization of VM
    Could not reserve enough space for object heap

    This sound to me like the hint from Chris, doesn’t it?
    As this is purely a test installation; where can I limit the MaxNewSize?
    Or is the “Error occurred during initialization of VM” a different problem apart from that?




    Hi Robert,

    sorry, the info you asked for:
    AMI ID: RHEL-6.4_GA-x86_64-10-Hourly2 (ami-75342c01)
    Nagios 03.05.2000
    Ganglia 03.05.2000



    Robert Molina

    Hi Manuel,
    I believe Chris is on it. Please try to provision a larger machine where Namenode can use around 1GB of memory.


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