A couple of days ago I was in an interesting call with two executives from Coraid: Kevin Brown (CEO) and his colleague Marcos Burnett (EMEA sales director). The following story is a resume of that call and a first introduction to Coraid technology and products.


Coraid is a small privately owned storage manufacturing company based in Silicon Valley and is in the market since 2004 with a family of Ethernet-based block Storage called EtherDrive. The company is experiencing a really interesting growth: in the last Q they tripled their revenues in a Y/Y comparison, most of the customers are in the US right now, but the management team is really committed to expand their operations in EMEA in the very next future.


As I mentioned above, Coraid EtherDrive is an ethernet storage. I think ethernet was chosen primarily due to the former experiences of its founders but, setting themselves apart from their competitors, Coraid isn’t using iSCSI nor FCoE but a protocol they are actively developing (available with an open source license and integrated into the Linux kernel too): ATA over Ethernet (AoE). One of the claimed advantages of AoE is that it’s not based on TCP/IP because it works directly on layer 2 (ethernet hardware) granting a lot of interesting features like: error checking and correction, a good reliability, a kind of automatic multipathing, a reduced latency and better throughput if compared to TCP based protocols.

We also need to remember that ethernet hardware can be very cheap and powerful while the development of next generation solutions are still in progress: we are now dealing with 1 and 10Gb networks but 40 and 100GBb are just around the corner.

architecture and products

Coraid has a massive scale out architecture and you can start very small, even with a single tray of disks, and then add more and more trays when needed for: space, throughput or IOPS.
The capability to build huge storage infrastructures (some coraid’s customers have more than 1 PB installed) doesn’t mean to have big storage expenses because, thanks to the extensive use of commodity hardware, Coraid claims 5-8 times better prices (TCA) than traditional FC storage. Well, I’m not very fond of TCA savings but if Coraid stuff is so cheap, I’m sure, it will find its place in a lot of markets like Video recording/streaming, archiving, HPC and so on.

If you browse the Coraid’s web site you’ll basically find two product lines: the SR/SRX shelves and the VSX series of virtualizing appliances.
The shelves, stuffed with different kinds of disks ranging from SSD, SAS down to SATA, are simple single controller arrays with up to four 10Gb ethernet ports and a very limited set of base functionalities. In practice, each shelf is raid protected and acts as a local disk connected to the servers via ethernet.
If you need more from your SAN you need to add a VSX appliance. In fact, VSX adds some enterprise features like snapshots, high availability volumes via a synchronous mirroring of LUNs between shelves and asynchronous remote replications. The VSX feature set is still limited, if compared to many other vendors, but it is more than enough for many enterprises, especially in the SMB segment.

final note

Coraid products aren’t what you would call “full-featured storage arrays” but their vision is more focused on simplicity and horsepower at a very cheap price. Out of there, many end customers are looking for these characteristics and it can be a good fit for them.
ESG produced very enthusiastic report and video on Coraid technology/products and I think they can be worth to watch and read if you want to understand more about this technology.