hadoop/hadoop-ozone/docs/content/RealCluster.md

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Starting an Ozone Cluster	1	main parent weight Starting 3

Before we boot up the Ozone cluster, we need to initialize both SCM and Ozone Manager.

{{< highlight bash >}} ozone scm -init {{< /highlight >}} This allows SCM to create the cluster Identity and initialize its state. The init command is similar to Namenode format. Init command is executed only once, that allows SCM to create all the required on-disk structures to work correctly. {{< highlight bash >}} ozone --daemon start scm {{< /highlight >}}

Once we know SCM is up and running, we can create an Object Store for our use. This is done by running the following command.

{{< highlight bash >}} ozone om -createObjectStore {{< /highlight >}}

Once Ozone manager has created the Object Store, we are ready to run the name services.

{{< highlight bash >}} ozone --daemon start om {{< /highlight >}}

At this point Ozone's name services, the Ozone manager, and the block service SCM is both running. Please note: If SCM is not running createObjectStore command will fail. SCM start will fail if on-disk data structures are missing. So please make sure you have done both init and createObjectStore commands.

Now we need to start the data nodes. Please run the following command on each datanode. {{< highlight bash >}} ozone --daemon start datanode {{< /highlight >}}

At this point SCM, Ozone Manager and data nodes are up and running.

Congratulations!, You have set up a functional ozone cluster.

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If you want to make your life simpler, you can just run {{< highlight bash >}} ozone scm -init ozone om -createObjectStore start-ozone.sh {{< /highlight >}} This assumes that you have set up the slaves file correctly and ssh configuration that allows ssh-ing to all data nodes. This is the same as the HDFS configuration, so please refer to HDFS documentation on how to set this up.