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Startup Excelero is the latest entrant in the market for high-performance storage based on nonvolatile memory express flash drives.
The Santa Clara, Calif., vendor came out of stealth this week with NVMesh Server SAN, software that pools unified NVMe storage for sharing across hundreds of server nodes. An NVMesh block driver installs on each server in a cluster. NVMe SSD capacity on one host is made available for consumption by all other hosts.
"We see a big need -- and not many solutions -- for a primary block storage I/O software layer within the premises of large data centers," said CTO Yaniv Romem. "We let you share NVMe drives across your data center. An application running on Machine A can consume storage from Machines B, C and D."
Although NVMesh Server SAN is generally available, Excelero has been in the market with proofs of concept since July 2016. Romem said the largest current production deployment encompasses 128 nodes and 250 TB of storage at the NASA Ames Research Center.
How NVMesh enables drive access
Hyperscale data centers use Excelero to cobble together a SAN-like environment from standard NVMe drives, network interface cards (NICs) and server hardware. Early customers include General Electric's Predix, Hulu, NASA and PayPal.
NVMesh Server SAN sits between block devices and logical file volumes. It uses a technique known as Remote Direct Drive Access (RDDA) to read and write data directly on an NVMe device.
RDDA is the vendor's twist on Remote Direct Memory Access (RDMA). It is a message-patching fabric that permits drives to be accessed without target-side CPU commands. Data services are shifted from centralized processors, allowing performance to scale linearly at nearly 100% efficiency.
Marc Staimersenior analyst, Dragon Slayer Consulting
RDDA uses RDMA over converged Ethernet technology to connect all the drives in a cluster. "It makes the NIC think it's writing to memory, when it's actually writing to the NVMe drive," Romem said.
Marc Staimer, senior analyst at Dragon Slayer Consulting in Beaverton, Ore., said Excelero's starting point is the high-performance computing market.
"It's different than a scale-up model [in which] the architecture controls all the performance," Staimer said. "Excelero allows an application to get direct access to the highest performing pieces across the board, whether it is on the same node as the application or not."
The RDDA technology does not depend on caching to alleviate latency. "This is cacheless performance. The data is not running in DRAM. If you lose power in a node and can't access those drives, you don't lose any data," Staimer said.
NVMesh can run in converged, disaggregated or mixed mode. The product also supports SAS- and SATA-based SSDs. NVMesh data management supports concatenated RAID 0, RAID 1 and RAID 10. Data is wide-striped across multiple server-based NVMe cards. The architecture detects domain failure at the host, rack and row level.
Excelero did not provide details on NVMesh pricing.
All-flash NVMe startups proliferate
Software-only Excelero joins a list of data storage startups developing all-flash products specifically for NVMe. Apeiron Data Systems, E8 Storage and Mangstor sell branded all-flash arrays outfitted with NVMe drives. Conversely, storage giant Dell EMC last week scrapped its NVMe-based DSSD D5 server flash platform.
Excelero's path to market depends on forging partnerships with established server vendors. NVMesh reference architecture is available for OpenStack clouds with Cinder, using Supermicro servers, Mellanox switching and off-the-shelf NVMe SSDs.
Excelero launched in Tel Aviv and has attracted two rounds of venture funding totaling $17.5 million. Primary Data CTO David Flynn is a private investor. Flynn was the founder of PCIe flash pioneer Fusion-io, acquired in 2014 by SanDisk Corp. (now part of Western Digital).
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