An emerging object-based storage device (OSD) architecture facilitates the creation of self-managed, secure, and shared storage. Despite of its potential of greatly improving the scalability and performance of distributed storage systems, only high-end applications direct their attentions to OSD. Currently, it is necessary for mid/entry-levels applications to employ the OSD technology. In this paper, we present OASIS, a cluster file system using OSD, which is designed to combine the iSCSI protocol with OSD SCSI. Our experiments show that our system matches up to performance of existing systems and achieves linear scalability of performance as the number of clients increased.