While OSCAR [1] has been conceived for clusters with disk(s) since its very first version, diskless (and systemless) support was a feature that lot of people expected. The Center for Scientific Computing [2] (CCS) has built several clusters without disk [3]. We tested OSCAR and were easily convinced of it’s quality and professionalism especially compared to our own home-made scripts. We decided to use OSCAR for our diskless cluster and then transfer our diskless expertise to the OSCAR project. The thinOSCAR [4] work-group was created to specifically analyze and solve problems that will arise while adding this diskless clusters support. We will first define essential notions for a diskless cluster. Then, the actual implementation of thin-OSCAR will be exposed. We will expose a « road-map » for the development of thin-OSCAR. Interaction with OSCAR will be detailed so that features can be discussed, prioritized and eventually added to the OSCAR framework.