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Excelero NVMesh 2 supports TCP/IP, Fibre Channel
Excelero's software-defined storage extends NVMe over fabrics support to TCP/IP and Fibre Channel, but the startup isn't abandoning NVMe over RDMA with its NVMesh 2.
Excelero will try to expand the reach of its NVMesh software by adding support for TCP/IP and Fibre Channel networking, distributed parity data protection and enhanced performance analytics.
Excerlero's NVMesh software-defined block storage focuses exclusively on nonvolatile express (NVMe) and NVMe over fabrics (NVMe-oF). Those technologies can significantly boost performance and lower latency over conventional flash options.
The Excelero NVMesh software is designed to virtualize and pool ultra-fast NVMe-based PCI Express (PCIe) SSDs. It lets applications access those SSDs across any network, optimally with just five microseconds of latency. Any host server running Excelero NVMesh client software can access the NVMe-based storage resources that are distributed across servers.
Excelero launched NVMesh 2 this week, building on NVMesh 1.1 released in March 2017. The previous version was all about remote direct access (RDMA) -- supporting InfiniBand and RDMA over Converged Ethernet (RoCe) version 2 networking -- and RAID 1.
Excelero NVMesh 2
Excelero NVMesh 2 will allow customers to use their TCP/IP and Fibre Channel network technologies, choose any type of erasure coding to protect their data, and build customized dashboards to analyze performance on a cluster-wide and per-object basis.
NVMe Mesh 2 will be generally available in January. Its capabilities include TCP and Fibre Channel support in MeshConnect, mirrored and parity-based redundancy in MeshProtect and MeshInspect performance analytics.
"The increase in flexibility is what stands out here," wrote Eric Burgener, a research vice president at IDC, in an email. "I expect their other startup competitors will move in similar directions, at least with NVMe-oF. Getting the TCP version of NVMe-oF will be big, especially when you're targeting webscalers like they are."
Burgener said "webscalers" -- such as e-commerce and internet dating sites -- run mixed workloads on commodity, scale-out server hardware with local storage, just as larger hyperscalers do. He said the unpredictability of those cloud-based workloads makes predictable low latency especially important because the webscalers often need to meet service-level agreements with their customers, even as demand varies.
NVMe over TCP/IP support
Excelero CEO and co-founder Lior Gal said the startup will support its "own flavor" of NVMe over TCP/IP until the standard is final, just as it did with RDMA. He said Excelero closely follows the work of the standards committee and would update the 20% of its "proprietary pre-standard" code that represents the transport layer once the NVMe/TCP specification is finished. Customers will not need to "rip and replace" any components to do the software upgrade, Gal said.
Gal said the TCP/IP option would not enable the five-microsecond latency that faster transport options do. But he said Excelero invested considerable engineering effort to enable NVMe over TCP/IP to open the barrier that RDMA-only options presented and facilitate wider adoption of NVMe-based technology. He said the same storage volume would now be accessible via TCP/IP, Fibre Channel or RDMA.
"Supporting TCI/IP doesn't mean anything bad about RDMA. We'll continue to sell into RDMA environments," Gal said. "But we need to listen to our customers and allow them to deploy stuff that is in line with their requirements. And 80% of their requirements is TCP/IP."
Gal said Excelero started working on erasure coding two years ago because RAID 1 would not be good enough for customers that want to extend their deployments beyond in-server NVMe to multiserver environments. He said Excelero primarily tested 8+2 erasure coding, with four SSDs for data and two for parity, but customers can choose whatever configuration they want.
Excelero sells its software through the channel and partners such as Quantum, CMA and Western Digital, which is also an investor. The company publishes a hardware compatibility list and asks customers or partners to let it know if they want to use different hardware, so it can pre-qualify and test other options to add to the list, Gal said.
List pricing for NVMesh starts at $2,400 per NVMe drive. Excelero also offers server-based pricing that bundles multiple drive costs into a single SKU.
Excelero NVMesh competition
IDC's Burgener said Excelero targets different customers than established enterprise storage vendors that sell NVMe-based arrays, including Dell EMC, IBM, NetApp and Pure Storage. He said Excelero NVMesh's low latency is its key differentiator.
Burgener said startups that compete with software-only Excelero include E8 Storage, Pavilion Data and Vexata. But he said Excelero is getting ahead of most of them with its support of the additional TCP and FC transport options with NVMe-oF.
"Also, [Excelero's] architecture runs the data services on the client side, rather than the target side, which is different from how the other startups are doing it," Burgener wrote. "This gives them more flexibility to run with different types of storage hardware, which is just servers with local storage."
