Though you can install OpenStack Object Storage for development or testing purposes on a single server, a multiple-server installation enables the high availability and redundancy you want in a production distributed object storage system.
If you would like to perform a single node installation on Ubuntu for development purposes from source code, use the Swift All In One instructions or DevStack. See http://swift.openstack.org/development_saio.html for manual instructions or http://devstack.org for all-in-one including authentication and a dashboard.
