62: GreyBeards talk NVMeoF storage with VR Satish, Founder & CTO Pavilion Data Systems

In this episode,  we continue on our NVMeoF track by talking with VR Satish (@satish_vr), Founder and CTO of Pavilion Data Systems (@PavilionData). Howard had talked with Pavilion Data over the last year or so and I just had a briefing with them over the past week.

Pavilion data is taking a different tack to NVMeoF, innovating in software and hardware design, but using merchant silicon for their NVMeoF accelerated array solution. They offer Ethernet based NVMeoF block storage.

VR is a storage “lifer“, having worked at Veritas on their Volume Manager and other products for a long time. Moreover, Pavilion Data has a number of exec’s from Pure Storage (including their CEO, Gurpreet Singh), other storage technology companies and is located in San Jose, CA.

VR says there were 5 overriding principles for Pavilion Data as they were considering a new storage architecture:

  1. The IT industry is moving to rack scale compute and hence, there is a need for rack scale storage.
  2. Great merchant silicon was coming online so, there was less of a need to design their own silicon/asics/FPGAs.
  3. Rack scale storage needs to provide “local” (within the rack) resiliency/high availability and let modern applications manage “global” (outside the rack) resiliency/HA.
  4. Rack scale storage needs to support advanced data management services.
  5. Rack scale storage has to be easy to deploy and run

Pavilion Data’s key insight was in order to meet all those principles and deal with high performance NVMe flash and up and coming, SCM SSDs,  storage had to be redesigned to look more like network switches.

Controller cards?

One can see this new networking approach in their bottom of rack, 4U storage appliance. Their appliance has up to 20 controller cards creating a heavy compute/high bandwidth cluster attached via an internal PCIe switch to a backend storage complex made up of up to 72 U.2 NVMe SSDs.

The SSDs fit into an interposer that plugs into their PCIe switch and maps single (or dual ported) SSDs to the applianece’s PCIe bus. Each controller card supports an Intel  XeonD micrprocessor and 2 100GbE ports for up to 40 100GbE ports per appliance. The controller cards are configured in an active-active, auto-failover mode, for high availability. They don’t use memory caching or have any NVram.

On their website Pavilion data show  117 µsec response times and 114 GB/sec of throughput for IO performance.

Data management for NVMeoF storage

Pavilion Data storage supports widely striped/RAID6 data protection (16+2), thin provisioning, space efficient read only (redirect on write) snapshots and space efficient read-write clones. With RAID6, it takes more than 2  drive failures to lose data.

Like traditional storage, volumes (NVMe namespaces) are assigned to RAID groups.  The backend layout appears to be a log structured file. VR mentioned that they don’t do garbage collection and with no Nvram/no memory caching, there’s a bit of secret sauce here.

Pavilion Data storage offers two NVMeoF/Ethernet protocols:

  • Standard off the shelf,  NVMeoF/RoCE interface that makes use of v1.x of the Linux kernel NVMeoF/RoCE drivers and special NIC/switch hardware
  • New NVMeof/TCP interface that doesn’t need special networking  hardware and as such, offers NVMeoF over standard NIC/switches. I assume this takes host software to work.

In addition, Pavilion Data has developed their own Multi-path IO (MPIO) driver for NVMeoF high availability which they have contributed to the current Linux kernel project.

Their management software uses RESTful APIs (documented on their website). They also offer a CLI and GUI, both built using these APIs.  Bottom of rack storage appliances are managed as separate storage units, so they don’t support clusters of more than one appliance. However, there are only a few cluster storage systems we know of that support 20 controllers today for block storage.

Market

VR mentioned that they are going after new applications like MongoDB, Cassandra, CouchBase, etc. These applications are designed around rack scaling and provide “global”, off-rack/cross datacenter availability themselves. But VR also mentioned Oracle and other, more traditional applications. Pavilion Data storage is sold on a ($/GB) capacity basis.

The system comes in a minimum, 5 controller cards-18 NVMe SSD configuration and can be extended in groups of 5 controllers-18 NVMe SSDs to the full 20 controller cards-72 NVMe SSDs.

The podcast runs ~42 minutes. VR was very knowledgeable about the storage industry, NVMeoF storage protocols, NVMe SSDs and advanced data management capabilities. We had a good talk with VR on what Pavilion Data does and how well it works.   Listen to the podcast to learn more.

VR Satish, Founder and CTO, Pavilion Data Systems

VR Satish is the Chief Technology Officer at Pavilion Data Systems and brings more than 20 years of experience in enterprise storage software products.

Prior to joining Pavilion Data, he was an Entrepreneur-in-Residence at Artiman Ventures. Satish was an early employee of Veritas and later served as the Vice President and the Chief Technology Officer for the Information & Availability Group at Symantec Corporation prior to joining Artiman.

His current areas of interest include distributed computing, information-centric storage architectures and virtualization.

Satish holds multiple patents in storage management, and earned his Master’s degree in computer science from the University of Florida.

Leave a Reply

Your email address will not be published. Required fields are marked *