Ethernet Storage: The future of storage area networking

Coraid aims to reduce the cost and complexity of storage by borrowing from the key lessons of the large scale web providers: leverage commodity hardware economics, simplify and automate, and build intelligence at the software layer.

Three keys to the Coraid technology vision

  • Ethernet Storage: A scale-out, connectionless, and massively parallel data architecture built on ATA over Ethernet (AoE). By leveraging the simple Layer 2 nature of Ethernet, AoE provides high throughput, low latency data access while virtually eliminating many management points that exist in today’s FC and iSCSI environments.
  • CorOS™: A distributed storage operating system with a shared global namespace. CorOS is designed to enable many individual systems to be managed as a single logical system, turning storage into a shared, global pool of disks. By wrapping the system with a modern RESTful API, storage can be provisioned and controlled programmatically.
  • Policy-based automation: A framework for defining and inheriting policies across storage resources. With a simple interface into a global pool of storage, many storage operations can be routinely automated. Coraid is building the tools and technology to enable instant provisioning, deep insight into performance and capacity, rapid remediation of resource contention, and intelligent reporting on usage, helping organizations move to self-service, scalable cloud architectures.

Ethernet as a reliable storage link layer

Ethernet has emerged as the single data link protocol of choice for all data types, enjoying a performance and price-performance advantage over Fibre Channel networks. The cost of a 10 GbE port has dropped below $400 while Ethernet speeds of 40 Gb/s and 100 Gb/s are on the horizon.

AoE is a purpose built protocol built on top of Ethernet. AoE is a connectionless network protocol that does not rely on a session or transport layer. Coraid’s AoE driver recognizes every port and will use all in parallel.  When an AoE target presents itself to the initiator, the driver will sense multiple unicast lanes between the server and storage without the need for a MPIO driver. When the OS drops an IO request (read or write) onto AoE, the driver will segment the IO into multiple “max MTU” Ethernet frames. These frames will be sent across every available HBA port as unicast AoE datagrams to the AoE target. Each of these datagrams must be acknowledged (with the unique correlation tag) prior to acknowledging the IO to the operating system, ensuring reliable delivery. By using multiple unicast lanes, Coraid’s implementation of AoE is able to achieve much higher throughput and lower latency (response times).

Leveraging trends in commodity hardware

AoE provides a low overhead, high performance, scalable method of transferring data from server to disk. Coraid builds on that foundation by leveraging commodity hardware to deliver a scale out storage layer that is fast and cost-effective. Each EtherDrive SRX shelf is simple to configure and setup, making it possible to add storage to a host in a matter of minutes. By combining SATA, SAS, and SSD, each shelf can be configured to meet any performance profile, providing flexibility in deployment and design.

BENEFIT Description

Performance

An EtherDrive SRX appliance can provide up to 1,800 MB/s in throughput or nearly 200,000 IOPS in 4U, scaling out to millions of IOPS per rack. Mixing SATA, SAS and SSDs enables performance fine tuning to meet any application need with the same building block.

Simplicity

EtherDrive simplifies storage by eliminating complex multi-pathing topologies and software, rigid topology design, and esoteric Fibre Channel configuration tasks.

Scalability

Performance and economics scale out linearly with capacity by simply adding another appliance to the network. AoE's massively parallel, connectionless architecture ensures direct access between server and storage, avoiding traditional controller bottlenecks.