Installing DC/OS is a complicated process to be covered here, and the instructions differ for each environment. Be sure to read through the documentation before you start this process. There are features, such as the number of masters or external persistent storage that must be enabled at install time and cannot be changed later without reinstalling. Installation instructions are available at https://dcos.io/docs/1.8/administration/installing/.
The easiest way to get Mesosphere up and running is to use the stack install on AWS or use ACS which runs Mesosphere.
There are a few things to be aware of if you are installing manually or on local hardware:
Nodes must have at least two cores or virtual processors.
DC/OS nodes must be running CoreOS 7, RHEL 7, or CoreOS.
All nodes in the cluster must have NTP enabled. NTP servers are set in
/etc/systemd/timesyncd.conf. After the NTP servers have been set, run