In this section, you create a cluster based on the specifications defined in the configuration file. To create a cluster, you use the command pcluster create and the –config (or -c) option to specify the configuration file you wish to use.

If you create your cluster without using the**–-config** (or **-c**) option, then AWS ParallelCluster uses the default configuration with the minimum requirements to get a cluster running. For example, the default configuration for head and compute nodes is *t2.micro* instances instead of *c4.xlarge*.

In your AWS Cloud9 terminal, run the following to create a cluster. Make sure that the configuration file path is correct.

$ time pcluster create hpc-cluster -c cluster-config.conf

Your cluster will take a few minutes to build. The creation status displays in your terminal. Once the cluster is ready, you should see a result similar to the one shown in the following image.

The cluster names must be unique, there can be only one cluster of a given name at any time on your account in a region.