Tag Archives: Open-Flow

GreyBeards talk scale-out storage with Coho Data CTO/Co-founder, Andy Warfield

Welcome to our fifth episode. We return now to an in-depth technical discussion of leading edge storage systems, this time with Andrew Warfield, CTO and Co-founder of Coho Data. Coho Data supplies VMware scale-out storage solutions with PCIe SSDs and disk storage using the NFS protocol. Howard and I talked with Andy and Coho Data at Storage Field Day 4 last November but we thought he was so interesting, he deserved a second conversation.

This months podcast comes in at a little over 40 minutes. I apologize for the occasional poor sound quality. I used WiFi while recording the call while recuperating from foot surgery. Hopefully, next month I will be back to my normal office and using LAN.

Andy comes at storage from a stint at XenSource and Citrix Systems and sees many parallels between server virtualization and storage. In the case of servers, CPUs had become so powerful that in order to take advantage of all that speed you needed to run multiple independent workloads using a non-intrusive hypervisor to coordinate it all. In storage, the case can be made that PCIe SSDs can now supply more IOPS and throughput than most single application can possibly use and the way to take effective advantage of that performance is to support multiple IO workloads using a non-intrusive storage hyper/supervisor to coordinate it all. For Coho Data, all IO lands on PCIe SSD first and then is only migrated to Disk if it’s cold enough not to warrant flash residency.

The other interesting thing about Coho Data was their inclusion of an OpenFlow SDN switch in their scale-out storage system. They use SDN switching to help implement the NFS presentation layer,  balance IO workload across different nodes and direct IO to an appropriate node.

Although, I may have made mention of using 8″ floppies to gather data from storage systems in the old days, contrary to popular myth I never played frisbee with them.

Listen to the podcast to learn more…

Andrew Warfield, CTO/Co-founder Coho Data


Andy is an established researcher in computer systems, specializing in storage, virtualization, and security. At Coho Data, Andy leads the technology vision and directs the engineering team in building elegant and functional systems that enable customers to focus on the data and applications instead of the underlying infrastructure that drives them. As a PhD student at the University of Cambridge, he was one of the original authors of the Xen hypervisor, and has since done award-winning research in virtualization and high availability. At XenSource and Citrix Systems, he was the Technical Director for Storage & Emerging Technologies.