Category Archives: Reviews

Hypervisor convergence: Nutanix paradigm

This morning I had the pleasure to attend a general demo from Alberto Filisetti about what Nutanix offers in the hyperconvergence market.
Nutanix based its datacenter on “building blocks”, each of them includes simply some servers and some storage, both standard, all managed by a “magic” software.
Their IT team had the idea to export this model on the enterprise virtual market. This idea was so successful that they were able to gain about 400 million dollar in 4 round fundings, and they’re going to be public in short time.
All this happened in USA. Nutanix landed in Europe in 2012, and suddenly they were successful. The VMware VSAN concept was in an embrional state inside Nutanix almost 5 years before VMware (note that EMC was the main shareholder)
Today Nutanix holds more than 50% of hyperconverged market, inside Gartner magic quadrand its position is the leaders quadrant – high vision and high execute.
The Nutanix “block” includes very standard computing hardware (Supermicro, Lenovo, Dell), managed by its real added value: the managing, orchestrator software, reachable even by API, and on it Nutanix assures reliability. Maybe the definition “orchestrator” is not completely suitable. Why uses standard hardware: for predictability of performances and to assure support by well-known vendors.
Which was the reason for this choise: latency is high when data reside on non-local storage. Implementing this solution, all the reads and writes happen locally.
The base unit so, it’s called a 2-unit “Block”, containing 2 or 4 servers, or “nodes”. In this way they’re able to become up&running in just 20 minutes after mounting in the rack.
As written above, inside a block you’ll find not only computational units, but even capacitivity power: disks, traditional and SSD aggregate only in one file system, connected by a 10Gbps ToR switch.
On every node runs a Nutanix Controller VM (CVM) that is the real brain of the whole system.  It resides on SSD and hosts the Nutanix software, serving all of the I/O operations for the hypervisor and all VMs running on that host. It’s hypervisor agnostic, his level is higher.
Among all the hypervisors, KVM is one of the less used because of its hard manageablity. Nutanix has a solution in this case too. They developed a kind of hypervisor based on KVM, Acropolis, that simplify its management. Just a note: Acropolis is just an option, it isn’t mandatory for the system.
You’ll find a very good and updated resource for all Nutanix structure at Nutanix Bible.
All the nodes are independent, from 3 to the infinite and could be added one at a time. Every node doesn’t add only computing (CPU and RAM) but also storage and IO since every of them brings a controller. Compared to an external storage so, these nodes have the advantage to grow in width, where the external ones have the same initial controllers as a funnel.
Geographical and multi direction DR is also included, RPO minimum 1h, or BC, but in this case latency can’t be higher than 5ms, or using a VMware streched cluster.
The main intention of Nutanix is to make the datacenter invisibile: before storage invisible and, at last, the whole virtualization and cloud invisible too.
The first step, hiding storage, is reached thanks to a fabric (Lenovo) distributing the file system and protecting it. at the beginning it was mainly used in VDI solution because of low latencies, today VDI represents only 30% of business, even thanks to applications certifications (just a.e.SAP, Splunk, MS Exchange).
Finally, virtualization and cloud invisibility: with Acropolis as a higher layer over hypervisors, and Prism, that manages all the hypervisors controllers, and even per-VM management, but in this case only for the servers running Acropolis. the wonder of this application is the one-click operation to add any eterogeneous hypervisor!
The same platform is issued in a community edition, of course with no support.
Now, to resume what’s inside the block: independent servers carrying and conected by 2/4 10Gb ports,redundancy ones and management ones. Adding a node means adding resources, computing and storage (3-direction growth). This growth could happen also with different hardware, in order to protect older investments.
Every software upgrade (for bugs solving, for customer requests and suggestions, and because of greater performances (usually from 20 to 80% more) is performed by one click, no interruptions, no vMotions, because upgrades happen in a CVM at a time using redundanced automation. Or manually, uploading an image that is processed by VMware automation.
Let’s have a look to the data flow, a. e. in a 3-nodes system: ESXi writes on traditional local disks and replicates to the neighboors 2 or 3 times according to the set policy, with a very low latency of nanoseconds. If and when a disk fails, metadata rbuild the data with no need of management, no need to wait for rebuild.
Reads take place on SSD, in case of vMotion data are relocalized on the new server. The data locality allows IOPS of 15-20k.
Conclusions, why should we choose Nutanix:
  1. dimensions, that means low power, low space needed;
  2. time to install;
  3. fast and easy to upgrade;
  4.  upgd veloce,
  5. data protection at 2 or 3 levels, and in case of DR, in a geographic way;
  6. high predicted performances;
  7. hypervisor agnostic, managed by a GUI;
  8. an high specialized and professional support, covering not only the software, but even the base hardware.
Some considerations: should we need more storage and nomore computing, they’ll provide a so called “passive node”: very low CPUs and RAM, with high capacity low performances storage, attached by network to the system
Other hardware could coexist, in his case this hardware wn’t have all the Nutanix software optimization.
Finally, I would underline once more that a cluster can be made with different hypervisors: one KVM, one ESXi, one Hyper-V, all controlled by Prism.
I can’t wait to have a test unit to verify all this!