Axellio, next gen, IO intensive server for RT analytics by X-IO Technologies

We were at X-IO Technologies last week for SFD13 in Colorado Springs talking with the team and they showed us their new IO and storage intensive server, the Axellio. They want to sell Axellio to customers that need extreme IOPS, very high bandwidth, and large storage requirements. Videos of X-IO’s sessions at SFD13 are available here.

The hardware

Axellio comes in 2U appliance with two server nodes. Each server supports  2 sockets of Intel E5-26xx v4 CPUs (4 sockets total) supporting from 16 to 88 cores. Each server node can be configured with up to 1TB of DRAM or it also supports NVDIMMs.

There are two key differentiators to Axellio:

  1. The FabricExpress™, a PCIe based interconnect which allows both server nodes to access dual-ported,  2.5″ NVMe SSDs; and
  2. Dense drive trays, the Axellio supports up to 72 (6 trays with 12 drives each) 2.5″ NVMe SSDs offering up to 460TB of raw NVMe flash using 6.4TB NVMe SSDs. Higher capacity NVMe SSDS available soon will increase Axellio capacity to 1PB of raw NVMe flash.

They also probably spent a lot of time on packaging, cooling and power in order to make Axellio a reliable solution for edge computing. We asked if it was NEBs compliant and they told us not yet but they are working on it.

Axellio can also be configured to replace 2 drive trays with 2 processor offload modules such as 2x Intel Phi CPU extensions for parallel compute, 2X Nvidia K2 GPU modules for high end video or VDI processing or 2X Nvidia P100 Tesla modules for machine learning processing. Probably anything that fits into Axellio’s power, cooling and PCIe bus lane limitations would also probably work here.

At the frontend of the appliance there are 1x16PCIe lanes of server retained for networking that can support off the shelf NICs/HCAs/HBAs with HHHL or FHHL cards for Ethernet, Infiniband or FC access to the Axellio. This provides up to 2x100GbE per server node of network access.

Performance of Axellio

With Axellio using all NVMe SSDs, we expect high IO performance. Further, they are measuring IO performance from internal to the CPUs on the Axellio server nodes. X-IO says the Axellio can hit >12Million IO/sec with at 35µsec latencies with 72 NVMe SSDs.

Lab testing detailed in the chart above shows IO rates for an Axellio appliance with 48 NVMe SSDs. With that configuration the Axellio can do 7.8M 4KB random write IOPS at 90µsec average response times and 8.6M 4KB random read IOPS at 164µsec latencies. Don’t know why reads would take longer than writes in Axellio, but they are doing 10% more of them.

Furthermore, the difference between read and write IOP rates aren’t close to what we have seen with other AFAs. Typically, maximum write IOPs are much less than read IOPs. Why Axellio’s read and write IOP rates are so close to one another (~10%) is a significant mystery.

As for IO bandwitdh, Axellio it supports up to 60GB/sec sustained and in the 48 drive lax testing it generated 30.5GB/sec for random 4KB writes and 33.7GB/sec for random 4KB reads. Again much closer together than what we have seen for other AFAs.

Also noteworthy, given PCIe’s bi-directional capabilities, X-IO said that there’s no reason that the system couldn’t be doing a mixed IO workload of both random reads and writes at similar rates. Although, they didn’t present any test data to substantiate that claim.

Markets for Axellio

They really didn’t talk about the software for Axellio. We would guess this is up to the customer/vertical that uses it.

Aside from the obvious use case as a X-IO’s next generation ISE storage appliance, Axellio could easily be used as an edge processor for a massive fabric of IoT devices, analytics processor for large RT streaming data, and deep packet capture and analysis processing for cyber security/intelligence gathering, etc. X-IO seems to be focusing their current efforts on attacking these verticals and others with similar processing requirements.

X-IO Technologies’ sessions at SFD13

Other sessions at X-IO include: Richard Lary, CTO X-IO Technologies gave a very interesting presentation on an mathematically optimized way to do data dedupe (caution some math involved); Bill Miller, CEO X-IO Technologies presented on edge computing’s new requirements and Gavin McLaughlin, Strategy & Communications talked about X-IO’s history and new approach to take the company into more profitable business.

Again all the videos are available online (see link above). We were very impressed with Richard’s dedupe session and haven’t heard as much about bloom filters, since Andy Warfield, CTO and Co-founder Coho Data, talked at SFD8.

For more information, other SFD13 blogger posts on X-IO’s sessions:

Full Disclosure

X-IO paid for our presence at their sessions and they provided each blogger a shirt, lunch and a USB stick with their presentations on it.


Coho Data, hyperloglog and the quest for IO performance

We were at SFD6, last month and Coho Data‘s CTO & Co-Founder, Andy Warfield got up to tell us what’s happening at Coho. (We also met with Andy at SFD4, check out the videolinks to learn more.)

What’s new at Coho Data

Coho Data has been shipping GA product for about 3 quarters and is a simple to use, scale-out, hybrid (SSD & disk) storage system for VMware NFS datastores. Coho Data storage uses Software Defined Networking (SDN) switches to perform faster networking handoffs and optimized data flow across storage nodes. They use standard servers and a SDN switch that can scale from two nodes (micro-arrays) to lots (100 or more?).

Version 2.0 will add remote asynch replication and enhanced API enhancements. We won’t discuss the update anymore but if you want your storage to tweet its messages/alerts check it out. Thank Chris Wahl when you start seeing storage system tweets pollute your  twitter feed.

The highlight of the session, was Andy’s discussion of HyperLogLog, a new approach to understanding customer workloads.


Coho Data was designed from the start using Microsoft IO traces (1-week of MSR Cambridge datacenter block IO traces available at SNIA IO Trace repository).  [bold italics added later, ed.] which recorded all IO from 10 But Coho also recorded linux developers developer desktop IO activity for a year, amounting to ~ 1B 7.6B IOs and multi-TBs of data. I just got a call looking for some file activity tracing, so everybody in storage could use more IO traces. But detailed IO traces take up CPU cycles and lot’s of space. HyperLogLogs can solve a portion of this.

Before we go there, a little background. For instance, with a Bloom Filter you can tell whether a block has been referenced or not. In a bloom filter you hash a key, term or whatever multiple times and then OR them into separate bitfields, one per hash. Bloom filters have a small possibility of a false positive (block-id present in filter but was not really in IO stream) but no possibility of a false negative (block-id NOT present in filter but it really was in IO stream). However, bloom filters tells us nothing about how frequently blocks were read.

With a HyperLogLog, one can approximate (within ~2%) how many times a block was referenced. By capturing multiple HyperLogLogs pictures over time, one can determine block access frequency during application processing. Each HyperLogLog trace only occupies ~2 KB, so recording one/hour takes ~50KB/day. The math is beyond me but there’s plenty info online (e.g. here).

HyperLogLog functionality will be included in a future Coho Data update. Coho Data will be implementing what they call “Counter Stacks” which makes use of hyperloglogs in a future release (see Jake Wire’s Usenix Session video/PDF)Once present, Coho Data will save hyperloglog counter stack data, analyze it, and use it to better characterize customer IO with the goal of better optimizing their storage system to actual workloads

For more info please see other SFD6 blogger posts on Coho Data:


Now if someone could just develop a super efficient algorithm/storage structure to record block sequences I think we have this licked.

Disclosure statement: I have done work for Coho Data over the last year.

Picture credits: (Lego) Me holding a Coho (Data) Salmon 🙂