Hardware consolidation in the datacenter occasionally leads to scalability bottlenecks due to the heavy utilization of critical resources, such as the shared network bandwidth. Storage virtualization at the file interface achieves clear consistency semantics, supports native file sharing between clients over different hosts, and provides flexible configuration of the durability time period at the host side. We improve the durability of shared storage in the proposed Arion system by supporting journaling at the kernel-level client of an object-based distributed filesystem. Over a prototype implementation of Arion that we developed, we experimentally demonstrate improved performance for specific durability guarantees, and reduced network and disk bandwidth at the storage servers. The scalable deployment of distributed filesystems in multitentant environments is challenging due to intermediate translation layers required for networked file access or identity management. We introduce the design of the Dike authorization architecture that combines native access control with tenant namespace isolation and compatibility to object-based filesystems. We use machines in a public cloud to experimentally evaluate a prototype implementation of Dike that we developed.

Stergios V. Anastasiadis is currently Academic Visitor at the Computer Laboratory, University of Cambridge, UK, on sabbatical leave from his tenured position as Associate Professor at the Department of Computer Science and Engineering, University of Ioannina, Greece. Previously he served visiting appointments at EPFL, Switzerland (2009-2010), the Technical University of Crete, Greece (2005), and Duke University, USA (2001-2003). He received MSc (1996) and PhD (2001) degrees in Computer Science from the University of Toronto, Canada, and did a research internship (1998) at HP Labs, USA. His research interests include operating systems and distributed systems with focus on data storage. For more info: www.cs.uoi.gr/~stergios