Posted on

68: GreyBeards talk NVMeoF/TCP with Ahmet Houssein, VP of Marketing & Strategy @ Solarflare Communications

In this episode we talk with Ahmet Houssein, VP of Marketing and Strategic Direction at Solarflare Communications, (@solarflare_comm). Ahmet’s been in the industry forever and has a unique view on where NVMeoF needs to go. Howard had talked with Ahmet at last years FMS. Ahmet will also be speaking at this years FMS (this week in Santa Clara, CA)..

Solarflare Communications sells Ethernet communication gear, mostly to the financial services market and has developed a software plugin for the standard TCP/IP stack on Linux that supports both target and client mode NVMeoF/TCP. That is, their software plugin provides a complete implementation of NVMeoF across TCP Ethernet that extends the TCP protocol but doesn’t require RDMA (RoCE or iWARP) or data center bridging.

Implementing NVMeoF/TCP

Solarflare’s NVMeoF/TCP is a free plugin that once approved by the NVMe(oF) standard’s committees anyone can use to create a NVMeoF storage system and consume that storage from almost anywhere. The standards committee is expected to approve the protocol extension soon and sometime after that the plugin will be added to the Linux Kernel. After standards approval, maybe VMware and Microsoft will adopt it as well, but may take more work.

Over the last year plus most NVMeoF/Ethernet we encounter requires sophisticated RDMA hardware. When we talked with Pavilion Data Systems, a month or so ago, they had designed a more networking like approach to NVMeoF using RoCE and TCP a special purpose FPGA that’s used in their RDMA NICs and Mellanox switches to support client-target mode NVMeoF/UDP [updated 8/8/18 after VR’s comment, the ed.]. When we talked with Attala Systems, they had special purpose FPGA that’s used in RDMA NICs and Mellanox switches to support target & client mode NVMeoF/UDP were using standard RDMA NICs and Mellanox switches to support their NVMeoF/Ethernet storage [updated 8/8/18 after VR’s comment, the ed.].

Solarflare is taking a different tack.

One problem with the NVMeoF/Ethernet RDMA is compatibility. You can use either RoCE or iWARP RDMA NICs but at the moment you can’t use both. With TCP/IP plugins there’s no hardware compatibility issue. (Yes, there’s software compatibility at both ends of the pipe).

SolarFlare recently measured latencies for their NVMeoF/TCP (Iometer/FIO) which shows that the with the protocol running it adds about a 5-10% increase in latency versus running RDMA NVMeoF/UDP-RoCE-iWARP.

Performance measurements were taken using a server, running Red Hat Linux + their TCP plugin with NVMe SSDs on the storage side and a similar configuration on the client side without the SSDs.

If they add 10% latency to 10 microsec. IO (for Optane), latency becomes 11 microsec. Similarly for flash NVMe SSDs it moves from 100 microsec to 110 microsec.

Ahmet did mention that their NICs have some hardware optimizations which brings down this added latency into something approaching closer to 5%. And later we discuss the immense parallelism opportunities using the TCP stack in user space. Their hardware also better supports more threads doing IO in parallel.

Why TCP

Ahmets on a mission. He says there’s this misbelief that Ethernet RDMA hardware is required to achieve lightening fast response times using NVMeoF, but it’s not true. Standard TCP with proper protocol enhancements is more than capable of performing at very close to the same latencies as RDMA, without special NICs and DCB switch configurations.

Furthermore, TCP/IP already has multipathing support. So current high availability characteristics of TCP are readily applicable to NVMeoF/TCP

Parallelism through user space

NVMeoF/TCP was the subject of 1st half of our discussion but we spent the 2nd half talking about scaling or parallelism. Even if you can do 11 or 110 microsecond latency at some point, if you do enough of these IOs, the kernel overhead in processing blocks and transferring control from kernel space to user space will become a bottleneck.

However, there’s nothing stopping IT from running the TCP/IP stack in user space and eliminating any kernel control transfer whatsoever. By doing so, data centers could parallelize all this IO using as many cores as available.

Running the plugin in a TCP/IP stack in user space allows you to scale NVMeoF lightening fast IO to as many users as you have user spaces or cores, and the kernel doesn’t even break into a sweat

Anyone could simply download Solarflare’s plugin, configure a white box server with Linux and 24 NVMe SSDs and support ~8.4M IOPS (350Kx24) at ~110 microsec latency And with user space scaling, one could easily have 1000s of user spaces connected to it.

They’re going to need need faster pipes!

The podcast runs ~39 minutes. Ahmet was very knowledgeable about NVMe, NVMeoF and TCP.  He was articulate and easy to talk with.  Listen to the podcast to learn more.

Podcast: Play in new window | Download (Duration: 38:50 — 53.3MB) | Embed

Subscribe: Apple Podcasts | Google Podcasts | Spotify | Stitcher | Email | RSS

Ahmet Houssein, VP of Marketing and Strategic Direction at Solarflare Communications 

Ahmet Houssein is responsible for establishing marketing strategies and implementing programs to drive revenue growth, enter new markets and expand brand awareness to support Solarflare’s continuous development and global expansion.

He has over twenty-five years of experience in the server, storage, data center and networking industry, and held senior level executive positions in product development, marketing and business development at Intel and Honeywell. Most recently Houssein was SVP/GM at QLogic where he successfully delivered first to market with 25Gb Ethernet products securing design wins at HP and Dell.

One of the key leaders in the creation of the INFINIBAND and PCI-Express industry standard, Houssein is a recipient of the Intel Achievement Award and was a founding board member of the Storage Network Industry Association (SNIA), a global organization of 400 companies in the storage market. He was educated in London, UK and holds an Electrical Engineering Degree equivalent.

Posted on

43: GreyBeards talk Tier 0 again with Yaniv Romem CTO/Founder & Josh Goldenhar VP Products of Excelero

In this episode, we talk with another next gen, Tier 0 storage provider. This time our guests are Yaniv Romem CTO/Founder  & Josh Goldenhar (@eeschwa) VP Products from Excelero, another new storage startup out of Israel.  Both Howard and I talked with Excelero at SFD12 (videos here) earlier last month in San Jose. I was very impressed with their raw performance and wrote a popular RayOnStorage blog post on their system (see my 4M IO/sec@227µsec 4KB Read… post) from our discussions during SFD12.

As we have discussed previously, Tier 0, next generation flash arrays provide very high performing storage at very low latencies with modest to non-existent advanced storage services. They are intended to replace server, direct access SSD storage with a more shared, scaleable storage solution.

In our last podcast (with E8 Storage) they sold a hardware Tier 0 appliance. As a different alternative, Excelero is a software defined, Tier 0 solution intended to be used on any commodity or off the shelf server hardware with high end networking and (low to high end) NVMe SSDs.

Indeed, what impressed me most with their 4M IO/sec, was that target storage system had almost 0 CPU utilization. (Read the post to learn how they did this). Excelero mentioned that they were able to generate high (11M random 4KB) IO/sec on  Intel Core 7, desktop-class CPU. Their one need in a storage server is plenty of PCIe lanes. They don’t even need to have dual socket storage servers, single socket CPU’s work just fine as long as the PCIe lanes are there.

Excelero software

Their intent is to bring Tier 0 capabilities out to all big storage environments. By providing a software only solution it could be easily OEMed by cluster file system vendors or HPC system vendors and generate amazing IO performance needed by their clients.

That’s also one of the reasons that they went with high end Ethernet networking rather than just Infiniband, which would have limited their market to mostly HPC environments. Excelero’s client software uses RoCE/RDMA hardware to perform IO operations with the storage server.

The other thing having little to no target storage server CPU utilization per IO operation gives them is the ability to scale up to 1000 of hosts or storage servers without reaching any storage system bottlenecks.  Another concern eliminated by minimal target server CPU utilization is that you can’t have a noisy neighbor problem, because there’s no target CPU processing to be shared.  Yet another advantage with Excelero is that bandwidth is only  limited by storage server PCIe lanes and networking.  A final advantage of their approach is that they can support any of the current and upcoming storage class memory devices supporting NVMe (e.g., Intel Optane SSDs).

The storage services they offer include RAID 0, 1 and 10 and a client side logical volume manager which supports multi-pathing. Logical volumes can span up to 128 storage servers, but can be accessed by almost any number of hosts. And there doesn’t appear to be a specific limit on the number of logical volumes you can have.

 

They support two different protocols across the 40GbE/100GbE networks. Standard NVMe over Fabric or RDDA (Excelero patented, proprietary Remote Direct Disk Array access). RDDA is what mainly provides the almost non-existent target storage server CPU utilization. But even with standard NVMe over Fabric they support low target CPU utilization. One proviso, with NVMe over Fabric, they do add shared volume functionality to support RAID device locking and additional fault tolerance capabilities.

On Excelero’s roadmap is thin provisioning, snapshots, compression and deduplication. However, they did mention that adding advanced storage functionality like this will impede performance. Currently, their distributed volume locking and configuration metadata is not normally accessed during an IO but when you add thin provisioning, snapshots and data reduction, this metadata needs to become more sophisticated and will necessitate some amount of access during and after an IO operation.

Excelero’s client software runs in Linux kernel mode client and they don’t currently support VMware or Hyper-V. But they do support KVM as a hypervisor and would be willing to support the others, if APIs were published or made available.

They also have an internal OpenStack Cinder driver but it’s not part of their OpenStack’s release yet. They’re waiting for snapshot to be available before they push this into the main code base. Ditto for Docker Engine but this is more of a beta capability today.

Excelero customer experience

One customer (NASA Ames/Moffat Field) deployed a single 2TB NVMe SSD across 128 hosts and had a single 256TB logical volume shared and accessed by all 128 hosts.

Another customer configured Excelero behind a clustered file system and was able to generate 30M randomized IO/sec at 200µsec latencies but more important, 140GB/sec of bandwidth. It turns out high bandwidth is important to many big data applications that have to roll lots of data into their analytics clusters, processing it and output results, and then do it all over again. Bandwidth limitations can impact the success of these types of applications.

By being software only they can be used in a standalone storage server or as a hyper-converged solution where applications and storage can be co-resident on the same server. As noted above, they currently support Linux O/Ss for their storage and client software and support any X86 Intel processor, any RDMA capable NIC, and any NVMe SSD.

Excelero GTM

Excelero is focused on the top 200 customers, which includes the hyper-scale providers like FaceBook, Google, Microsoft and others. But hyper-scale customers have huge software teams and really a single or few, very large/complex applications which they can create/optimize a Tier 0 storage for themselves.

It’s really the customers just below the hyper-scalar class, that have similar needs for high low latency IO/sec or high IO bandwidth (or both) but have 100s to 1000s of applications and they can’t afford to optimize them all for Tier 0 flash. If they solve sharing Tier 0 flash storage in a more general way, say as a block storage device. They can solve it for any application. And if the customer insists, they could put a clustered file system or even an object storage (who would want this) on top of this shared Tier 0 flash storage system.

These customers may currently be using NVMe SSDs within their servers as a DAS device. But with Excelero these resources can be shared across the data center. They think of themselves as a top of rack NVMe storage system.

On their website they have listed a few of their current customers and their pretty large and impressive.

NVMe competition

Aside from E8 Storage, there are few other competitors in Tier 0 storage. One recently announced a move to an NVMe flash storage solution and another killed their shipping solution. We talked about what all this means to them and their market at the end of the podcast. Suffice it to say, they’re not worried.

The podcast runs ~50 minutes. Josh and Yaniv were very knowledgeable about Tier 0, storage market dynamics and were a delight to talk with.   Listen to the podcast to learn more.

Podcast: Play in new window | Download (Duration: 50:06 — 23.0MB) | Embed

Subscribe: Apple Podcasts | Google Podcasts | Spotify | Stitcher | Email | RSS


Yaniv Romem CTO and Founder, Excelero

Yaniv Romem has been a technology evangelist at disruptive startups for the better part of 20 years. His passions are in the domains of high performance distributed computing, storage, databases and networking.
Yaniv has been a founder at several startups such as Excelero, Xeround and Picatel in these domains. He has served in CTO and VP Engineering roles for the most part.


Josh Goldenhar, Vice President Products, Excelero

Josh has been responsible for product strategy and vision at leading storage companies for over two decades. His experience puts him in a unique position to understand the needs of our customers.
Prior to joining Excelero, Josh was responsible for product strategy and management at EMC (XtremIO) and DataDirect Networks. Previous to that, his experience and passion was in large scale, systems architecture and administration with companies such as Cisco Systems. He’s been a technology leader in Linux, Unix and other OS’s for over 20 years. Josh holds a Bachelor’s degree in Psychology/Cognitive Science from the University of California, San Diego.
Posted on

42: GreyBeards talk next gen, tier 0 flash storage with Zivan Ori, CEO & Co-founder E8 Storage.

In this episode, we talk with Zivan Ori (@ZivanOri), CEO and Co-founder of E8 Storage, a new storage startup out of Israel. E8 Storage provides a tier 0, next generation all flash array storage solution for HPC and high end environments that need extremely high IO performance, with high availability and modest data services. We first saw E8 Storage at last years Flash Memory Summit (FMS 2016) and have wanted to talk with them since.

Tier 0 storage

The Greybeards discussed new tier 0 solutions in our annual yearend industry review podcast. As we saw it then, tier 0 provides lightening fast (~100s of µsec) read and write IO operations and millions of IO/sec. There are not a lot of applications that need this level of speed and quantity of IOs but for those that do, Tier 0 storage is their only solution.

In the past Tier 0, was essentially SSDs sitting on a PCIe bus, isolated to a single server. But today, with the emergence of NVMe protocols and SSDs, 40/50/100GBE NICs and switches and RDMA  protocols, this sort of solution can be shared across from racks of servers.

There were a few shared Tier 0 solutions available in the past but their challenge was that they all used proprietary hardware. With today’s new hardware and protocols, these new Tier 0 systems often perform as good or much better than the old generation but with off the shelf hardware.

E8 came to the market (emerged out of stealth and GA’d in September of 2016) after NVMe protocols, SSDs and RDMA were available in commodity hardware and have taken advantage of all these new capabilities.

E8 Storage system hardware & software

E8 Storage offers a 2U HA appliance with 24, hot-pluggable NVMe SSDs connected to it and support 8 client or host ports. The  hardware appliance has two controllers, two power supplies, and two batteries. The batteries are used to hold up a DRAM write cache until it can be flushed to internal storage for power failures. They don’t do any DRAM read caching because the performance off the NVMe SSDs is more than fast enough.

The 24 NVMe SSDs are all dual ported for fault tolerance and provide hot-pluggable replacement for better servicing in the field. One E8 Storage system can supply up to 180TB of usable, shared NVMe flash storage.

E8 Storage uses RDMA (RoCE) NICs between client servers and their storage system, which support 40GBE, 50GBE or 100GBE networking.

E8 does not do data reduction (thin provisioning, data deduplication or data compression) on their storage, so usable capacity = effective capacity.  Their belief is that these services consume a lot of compute/IO limiting IO/sec and increasing response times and as the price of NVMe SSD capacity is coming down over time these activities become less useful.

They also have client software that provides a fault tolerant initiator for their E8 storage. This client software supports MPIO and failover across controllers in the event of a controller outage. The client software currently runs on just about any flavor of Linux available today and E8 is working to port this to other OSs based on customer requests.

Storage provisioning and management is through a RESTful API, CLI or web based GUI management portal. Hardware support is supplied by E8 Storage and they offer a 3 year warranty on their system with the ability to extend this to 5 years, if needed.

One problem with today’s standard NVMe over Fabric solutions is that they lack any failover capabilities and really have no support for data protection. By developing their own client software, E8 provides fault tolerance and data protection for Tier 0 storage. They currently supported RAID 0 and 5 for E8 Storage and RAID 6 is in development.

Performance

Everyone wants native DAS-NVMe SSD storage but unlike server Tier 0 solutions, E8 Storage’s 180TB of NVMe capacity can be shared across up to 100 servers (currently have 96 servers talking to a single E8 Storage appliance at one customer).  By moving this capacity out to a shared storage device it can be be made more fault tolerant, more serviceable and be amortized over more servers. However the problem with doing this has always been the lack of DAS like performance.

Talking to Zivan, he revealed that a single E8 Storage service was capable of 5M IO/sec, and at that rate, the system delivers an average response time of  300µsec and for a more reasonable 4M IO/sec, the system can deliver ~120µsec response times. He said they can saturate a 100GBE network by operating at 10M IO/sec. He didn’t say what the response time was at 10M IO/sec but with network saturation, response times probably went exponentially higher.

The other thing that Zivan mentioned was that the system delivered these response times with a very small variance (standard deviation). I believe he mentioned 1.5 to 3% standard deviations which at 120µsec is 18 to 36µsec and even at 300µsec its 45 to 90µsec. We have never see this level of response times, response time variance and IO/sec in a single shared storage system before.

E8 Storage

Zivan and many of his team previously came from IBM XIV storage. As such, they have  been involved in developing and supporting enterprise class storage systems for quite awhile now. So, E8 Storage knows what it takes to create products that can survive in 7X24, high end, highly active and demanding environments.

E8 Storage currently has customers in production in the US. They are seeing primary interest  in their system from the HPC, FinServ, and Retail industries but any large customers could have the need for something like this.  They sell their storage for from $2 to $3/GB.

The podcast runs ~42 minutes, and Zivan was easy to talk with and has a good grasp of the storage industry technologies.  Listen to the podcast to learn more.

Podcast: Play in new window | Download (Duration: 42:07 — 19.3MB) | Embed

Subscribe: Apple Podcasts | Google Podcasts | Spotify | Stitcher | Email | RSS

Zivan Ori CEO & Co-Founder, E8 Storage

Mr. Zivan Ori is the co-founder and CEO of E8 Storage. Before founding E8 Storage, Mr. Ori held the position of IBM XIV R&D Manager, responsible for developing the IBM XIV high-end, grid-scale storage system, and served as Chief Architect at Stratoscale, a provider of hyper-converged infrastructure.

Prior to IBM XIV, Mr. Ori headed Software Development at Envara (acquired by Intel) and served as VP R&D at Onigma (acquired by McAfee).

Posted on

40: Greybeards storage industry yearend review podcast

In this episode, the Greybeards discuss the year in storage and naturally we kick off with the consolidation trend in the industry and the big one last year, the DELL-EMC acquisition. How the high margin EMC storage business is going to work in a low margin company like Dell is the subject of much speculation. That and which of the combined companies storage products will make it through the transition make for interesting discussions. And Finally what exactly is Dell’s long term strategy is another question.

We next turn to the coming of age of object storage. A couple of years ago, object storage was being introduced to a wider market but few wanted to code to RESTful interfaces. Nowadays, that seems to be less of a concern and the fact that one can have onsite/offsite/cloud based object storage repositories from open source, proprietary solutions and everything in between is making object storage a much more appealing option to enterprise IT.

Finally, we discuss the new Tier 0. What with NVMe SSDs and the emergence of NVMe over Fabric coming out last year, Tier 0 has never looked so promising.  You may recall that Tier 0 was hot about 5 years with TMS and Violin and others coming out with lightning fast storage IO. But with DELL-EMC DSSD: startups (E8 storage, Mangstor, Apeiron data systems, and others); NVMDIMMs, CrossBar, and Everspin coming out with denser offerings; and other SCM (Micron, HPE, IBM, others?) technologies on the horizon, Tier 0 has become red hot again.

Sorry about the occasional airplane noise and other audio anomalies. The podcast runs  over 47 minutes. Howard and I could talk for hours on what’s happening in the storage industry. Listen to the podcast to learn more.

Podcast: Play in new window | Download (Duration: 47:35 — 21.8MB) | Embed

Subscribe: Apple Podcasts | Google Podcasts | Spotify | Stitcher | Email | RSS

Ray Lucchesi is the President and Founder of Silverton Consulting, a prominent blogger at RayOnStorage.com, and can be found on twitter @RayLucchesi.

Howard Marks is the Founder and Chief Scientist of howardmarksDeepStorage, a prominent blogger at Deep Storage Blog and can be found on twitter @DeepStorageNet.