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Coho Data goes all-flash with new scale-out array

Coho Data, which sells scale-out NAS built on commodity hardware, adds the DS2000f that combines PCI Express flash and solid-state drives.

Startup Coho Data today added an all-flash version of its scale-out NAS storage system based on commodity hardware and designed for heavily virtualized VMware workloads.

The vendor also closed a $30 million funding round, bringing its total funding to $67 million.

The new DS2000f uses the same basic DataStream architecture as the DS1000h hybrid model already on the market. The difference is that the DS1000h combines PCI Express (PCIe) flash and hard disk drives (HDDs) while the all-flash DS2000f uses PCIe flash and solid-state drives (SSDs) with no spinning disk.

Coho Data claims the DS2000f can deliver 320,000 IOPS in each 2U chassis, using Intel P3600 NVMe flash with SSDs.

Each DS2000f consists of two nodes -- called MicroArrays -- in a 2U chassis that includes four 1.6 TB PCIe cards, up to 24 2.5-inch SSDs, four 10 Gigabit Ethernet cards and four Intel Xeon CPUs. A DS2000f chassis can hold between 7 TB and 47 TB of usable capacity before compression. It supports 1 TB, 2 TB and 4 TB SSDs. The dual MicroArrays present high availability -- if one fails, the other has a copy of the data.

Coho Data uses hardware from Supermicro, but CEO Ramana Jonnala said his company's software can run on any vendor's hardware. He said the current products can also support newer SSDs and capacities as they become available, allowing customers to run the latest technology in their storage systems already in production.

A DataStream controller switch handles data placement and routing to PCIe, SSDs or HDDs, and load balancing between tiers. The OpenFlow switch runs Coho Data software. A global namespace spans Coho Data's all-flash and hybrid arrays.

Jonnala said the ability to pool hybrid and all-flash arrays gives his company a leg up on all-flash vendors.

"You can mix PCIe flash and spinning disk or PCIe flash and SSD with our systems," he said. "The all-flash folks are selling scale-up systems but you're buying into a separate tier. You cannot have a hybrid combination and file systems across their all-flash and other tiers. We provide a permanent namespace for files and objects."

Jonnala said inline data duplication is on Coho Data's roadmap, along with cloud connectivity.

Coho Data uses a perpetual license pricing model that comes to approximately $2 per GB for the all-flash system. "You can run this box until it falls over, we don't lock customers into two-year, three-year or five-year support contracts," Jonnala said.

Jonnala said common use cases for DataStream systems include "power" virtual desktop infrastructure (CAD and frequently backed up desktops), Oracle databases running natively or in VMware ESX, and Hadoop. He said customers run Hadoop natively on Coho Data storage. "We take the HDFS [Hadoop Distributed File System] stack, containerize it, and run it on our box," he said.

He said Coho Data's goal is to build hyper-scale type storage like that used by Google and Facebook that allows customers to easily add capacity and performance.

"We are trying to break the way storage is purchased," Jonnala said. "EMC, NetApp and all these other storage vendors are good at convincing customers what they need three to five years in advance and selling them that. The customer is locked in. We make it dead simple for customers to grow. You add capacity or performance by sliding in another pizza box on the fly."

The independent Evaluator Group tested DS2000f performance and linear scalability by running its IOmark-VM benchmark. Evaluator Group analyst Russ Fellows said a one-node chassis achieved a 448 IOmark-VM benchmark and a two-chassis system ran up a 960 score, the highest result of any system tested. That means the one-node system could support 448 virtual application workloads (at a cost of $357.14 per VM) and the two-node system supported 960 VM workloads (for $302.08 per VM).

"The way Coho distributes and routes data is through its OpenFlow switch, which uses [software-defined networking] SDN," Fellows said. "So unlike many of the iSCSI scale-out designs, which typically redirect I/O from one node to another, the Coho approach redirects I/O at the switch. This eliminates the back channel traffic, or intra-node I/O that creates overhead that is common with other scale-out systems."

Fellows added that Coho Data's scalability does have a practical limit due to the number of SDN switch ports available. Another limitation is that Coho Data only works with VMware virtual applications.

Coho Data's $30 million funding round brought three new investors. March Capital Partners led the round, and Hewlett-Packard Ventures and Intel Capital joined. Previous Coho Data investors Andreessen Horowitz and Ignition Partners also participated.

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