Nutanix: Drop It Like It’s Hot

Nutanix is all in one solution building block for virtualization. It allows you to virtualize your workloads without requiring a SAN. This approach allows for many benefits, such as buy what you need, when you need it and a reduction in complexity around architecture and operations. I see Nutanix as perfect fit for VDI and Cloud workloads. Where there is uncertainty in the workload and large scale is needed, Nutanix can make a great fit.

Below is how their storage works inside of their 2U building blocks that contain 4 separate nodes. The Name of operating system Nutanix runs on is called HOT(Heat Optimized Tiering). The controller VM is the magic sauce of the operation. All the I\O flows through the controller VM. As data is written to the Fusion-IO card and then is serialized. When the data is cold , it will be laid out to disk in a nice clean format.

The SATA SSD is for ESXi, the Controller VM and VM Swap, nothing else gets to live here.

Write IO - Data is always written locally. Data is replicated on other nodes for high availability. Replica's are spread aacross the cluster for high performance.

Read IO - Nutanix

Read IO - All data is read locally, Remote access of data only if the data does not exist locally

Nutanix was built around iSCSI but now have the ability to run NFS as well. Nutanix calls their implementation of NFS, NDFS. It’s a really crazy bit of abstraction. Each VM is basically getting its own iSCSI LUN. Of course you don’t see any of that under the covers stuff. With their release of NDFS they have re-written the standard NFS code to turn allow for better performance. NFS was built to house thousands and thousands of files, today with virtualization it’s almost the opposite. With VMware we have large files, known as VMDK’s that containerize all the smaller files. Nutantix has tuned their implementation of NFS to work with few files large files instead of the old paradigm. NDFS can localize NFS client-server communication giving it the shortest path on the IO highway at all times.

Nutanix supports VAAI (vStorage APIs for Array Integration )and VCAI (View Composer Array Integration) and provide thier own command line interface called nCLI.

Some other articles on Nutanix

How Sales To Government Help Storage Start-Up Nutanix

Nutanix announces more vSphere integration features

Check out all the inter-workings in this Video from Tech Fied day

Nutanix Presents at Tech Field Day 8 from Stephen Foskett on Vimeo.


  1. I am very surprised and confused at the same time by the claims made here.
    First of all cache in fusion-io is always going to be lot less than total storage, so how is this solution going to work for true random reads ?
    Also your local disk storage can never come close to SAN storage in terms of capacity, so you can not fully replace SAN with local storage.
    In case of cloud deployments the use case scenarios are very limited today but this architecture won’t be enough for true enterprise applications if they have to run in cloud.
    This is nothing but a solution that will reduce latency in some limited number of scenarios. So why is it worth so much money ?

    • Hi Chandra

      Thanks for visiting my blog, I will try and answer your questions one at time.

      Reads – Stargate will move data back into PCI-SSD tier based on access patterns. If that data is only being it once in a blue moon I don’t think this will matter much. Do you have a specific use case? The Controller VM(CVM) that acts as the Storage Processor in traditional terms also has a read cache, we call it a Cache extent internally. If you have a really big read workload you can actually add more memory to the CVM and it adjust the Cache extent automatically. There a way to tell your cache hits/misses on the system.

      Storage – Nutanix’s bread and butter is software. I think you see some impressive things on the capacity front from Nutanix. Today we offer both inline and post-process(async) compression to go along with the raw 20TB over 4 nodes. The capacity will be going up. We don’t have worry about RAID either and the long rebuild time associated.

      Cloud & Enterprise Ent – We aren’t everything to everyone today. We’ve have had 3 major releases in the course of one year, unheard of with existing vendors. Lots of Enterprise apps don’t belong in the cloud. Regular Server virt gets labeled as private cloud and it isn’t the same. Nutanix is really could lots of VM’s and can levitate pain points due “overcrowding of resources”. Most server virt is great over time but then as Ops keeps adding VM’s due to business pressure, the performance drops off. With Nutanix you get a predictable, repeatable model for every node you add. I think most Enterprise’s would love to scale the IO and number of Storage controllers every time they add more compute.
      I really like the views posted on cloud in this article – http://gigaom.com/cloud/the-cloud-backlash-could-be-deep/

      Today every node you add is going additional 5,000 IOPS of capacity(20,000 IOPS per block), very few apps need more than that. We aren’t trying to cater to Moster VM’s because for the most part the live in the land of make believe.

      Cost – We are 30 % cheaper than our competitors on list price. To my knowledge we have never lost a deal to pricing when comparing the same about of storage and compute power.

  2. Nutanix says that they cut out the bottle necks being the controller, which is true in most architectures, but which controllers are they cutting out , front end or backend ? Also I heard that nutanix believes that iops are not so important , why is this ? With Xtreme IO from EMC and Pure fall flash arrays, this is what they primarily focus on.

    • dlessner says:

      I am not sure what you mean about front-end or back-end. Most cases people are referring to the the traditional SAN controllers and only having two of them. You still need disk controllers locally but that goes without saying. To IOPS is like a who has the bigger toy contest. Throughput, block size and latency are better things to look at. Typically Nutanix has more burst IOPS than most people can ever use. Typically limits in RAM and CPU are hit before IOPS on Nutanix. Nutanix is not just storage, it’s a solution. Only looking at storage will not give you the most robust design. Those products you mention are good but how do you add in the other pieces?, how do you maintain them?, how do you scale them?, so on and so fourth.

      • Thanks for your response, iv been doing abit of reading around Nutanix and building a business case and I like the fact as you mentioned that it is not just storage. I hope to bring some new questions to you soon!


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