I can confirm that the following json works to run-once a vm via rest, notice there are some differences to the json submitted by juan. I don't use this to create and start the vm in one step, the vm is already created: {"vm":{"initialization":{"cloud_init":{"host":{"address":"test"},"network_configuration":{"nics":{"nic":[{"name":"eth0","boot_protocol":"STATIC","network":{"ip":{"address":"10.211.0.244","netmask":"255.255.255.248","gateway":"10.211.0.241"}},"on_boot":true}]},"dns":{"servers":{"host":[{"address":"46.30.62.99"},{"address":"46.30.62.98"},{"address":"46.30.62.97"}]}}},"users":{"user":[{"name":"root","password":"#9Dh2--3xz-h95Zy"}]},"files":{"file":[{"name":"\/foo\/test","content":"test","type":"PLAINTEXT"}]}}}}} -- Mit freundlichen Grüßen / Regards Sven Kieske Systemadministrator Mittwald CM Service GmbH & Co. KG Königsberger Straße 6 32339 Espelkamp T: +49-5772-293-100 F: +49-5772-293-333 https://www.mittwald.de Geschäftsführer: Robert Meyer St.Nr.: 331/5721/1033, USt-IdNr.: DE814773217, HRA 6640, AG Bad Oeynhausen Komplementärin: Robert Meyer Verwaltungs GmbH, HRB 13260, AG Bad Oeynhausen