# Preparation of target machines

Currently, the machines needs to have at least 2 disk partitions :
 - 1 partition for the Operating System (**REQUIRED**)
 - 1 LVM partition for the Docker Storage (**REQUIRED**)

A third partition is recommended but not required :
 - 1 partition for the OpenShift Persistent Volumes (**OPTIONAL**)

If your machine has only one disk, you can create partitions (that may use LVM underneath or not, free choice).
An alternative when using Virtual Machines is to add 3 disks to the VM, the setup is a bit easier.

The OS partition is created by the RHEL installer so you do not have to care much about it.

The Docker Storage partition **has to be LVM** and **has to be in a separate Volume Group**.
Namely, if your Docker Storage partition is `/dev/sda2`, you can create a separate Volume Group by using :
```
vgcreate docker /dev/sda2
```

The OpenShift Persistent Volumes partition, if not required is still highly recommended.
By a having a dedicated partition, if the Persistent Volumes start to grow it will not
fill up the OS partition.

If your OpenShift PV partition is `/dev/sda3`, you can set it up by using :
```
mkfs.xfs /dev/sda3
echo "/dev/sda3 /var/openshift xfs defaults 0 0" >> /etc/fstab
```

If you kept the default values (`docker` for the Volume Group name and
`/var/openshift` for the OpenShift PV mount point), no further setup is required.

Otherwise, you might have to set the following variables in your inventory file :
 - `docker_storage_vg`
 - `hostpath_provisioner_options`