// Module included in the following assemblies:
//
// * rosa_cluster_admin/rosa_nodes/rosa-managing-worker-nodes.adoc

:_mod-docs-content-type: PROCEDURE
[id="configuring-machine-pool-disk-volume-cli_{context}"]
= Configuring machine pool disk volume using the ROSA CLI

.Prerequisite for cluster creation

* You have the option to select the root disk sizing for the default machine pool during cluster installation.

.Procedure for cluster creation

* Run the following command when creating your OpenShift cluster for the desired root disk size:
+
[source,terminal]
----
$ rosa create cluster --worker-disk-size=<disk_size>
----
The value can be in GB, GiB, TB, or TiB. Replace `<disk_size>` with a numeric value and unit, for example `--worker-disk-size=200GiB`. You cannot separate the digit and the unit. No spaces are allowed.

.Prerequisite for machine pool creation

* You have the option to select the root disk sizing for the new machine pool after the cluster has been installed.

.Procedure for machine pool creation

. Scale up the cluster by executing the following command:
+
[source,terminal]
----
$ rosa create machinepool --cluster=<cluster_id> \// <1>
                          --disk-size=<disk_size> // <2>
----
<1> Specifies the ID or name of your existing OpenShift cluster.
<2> Specifies the worker node disk size. The value can be in GB, GiB, TB, or TiB. Replace `<disk_size>` with a numeric value and unit, for example `--disk-size=200GiB`. You cannot separate the digit and the unit. No spaces are allowed.

. Confirm new machine pool disk volume size by logging into the AWS console and find the EC2 virtual machine root volume size.