Dare2Compare Part 6 : Nutanix data efficiency stats can’t be found

If you’ve not read Parts 1 through 5, we have already proven several claims by HPE Simplivity regarding Nutanix to be false, as well as explored the misleading way in which HPE SVT promote data efficiency.

We continue with Part 6 where we will discuss HPE’s claim that “Nutanix data efficiency stats are stealthier than a ninja”. (below)

While HPE’s claim is an attempt to create Fear, Uncertainty and Doubt (FUD), HPE are partially correct in that we (Nutanix) have done a very poor job of promoting the arguably market leading data efficiency that Nutanix provides.

In fact, several colleagues and I created a feature request to properly report in a clear and detailed way, the ADSF data efficiencies and I am pleased to say these changes were included as part of the recent AOS 5.1 release.

Now what Nutanix users see in PRISM “Storage” view is (as shown below):

  1. A Capacity optimization overview
  2. Data reduction ratio which is made up of deduplication, compression and erasure coding savings*.
  3. Data reduction savings which is a total GB/TB/PB value from data reduction
  4. An Overall Efficiency ratio which is a combination of Data Reduction, Cloning and Thin Provisioning

*Metadata copies/snapshops/pointers etc are not included in the deduplication value as they are not deduplication.

The resulting summary is very clear and easy to understand so customers can see what efficiencies are from data reduction, and which savings (which typically form by far the largest “efficiency”) come from Cloning and thin provisioning.


One major item which will be included in an upcoming release is zero suppression. Zero suppression is a capability which has been in Nutanix Distributed Storage Fabric since Day 1 and it avoids unnecessarily storing zeros, instead storing metadata which achieves the same outcome but is much higher performance and uses much less capacity.

Nutanix snapshots or pointer based copies (depending on how you refer to them) are also not included in the overall efficiency number, however these will also be included as a seperate line item in a future release as we aim to be very clear regarding what data efficiencies a customer is achieving with Nutanix.

Some vendors recommend Eager Zero Thick (EZT) VMDKs on vSphere, and then deduplicate the zeros which artificially increases the deduplication ratio. Nutanix does not do this as it’s inefficient to create more data to deduplicate when you can simply avoid writing the data in the first place. However we do plan to report the savings from Zero suppression as a seperate line item as it is a value our platform provides.

For a more detailed view, Nutanix customers can dive down into the storage,Diagram view where admins can view of each containers data efficiency breakdown (as shown below).


As we can see, Nutanix is very transparent showing what data reduction features are enabled, what ratio is being achieved, the total, used, reserved and even Thick Provisioned storage with an effective free based on physical multiplied by data reduction ratio and an overall efficiency value.

Now that we’ve covered off how Nutanix measures and reports on data reduction/efficiency, I’d like to highlight a critical factor when discussing data reduction/efficiency and that is that data efficiency is totally dependant on the individual customers data. For the same dataset, the difference between vendors with the same capabilities, e.g.: Deduplication, Compression and Erasure Coding (EC-X) are unlikely to be vastly different (or better put, change a business outcome one way or another) despite what each vendor will say about their implementation of such technologies.

In short: The biggest factor in the achieved data reduction is not the vendor, it’s the customer data.

With that said, if you’re comparing HPE SVT and Nutanix, then there is a pretty major delta between the two products in terms of capabilities and that is because Nutanix supports Erasure Coding (EC-X) and HPE SVT does not.

As a result, Nutanix has a major advantage as Erasure Coding in the Nutanix Acropolis Distributed Storage Fabric (ADSF) is complimentory to both deduplication and compression.

Unlike Compression and Deduplication, Erasure Coding can provide savings (or another way to look at it would be lower data redundancy overheads) regardless of the data type.

So where Deduplication and Compression will get minimal/no savings for data such as Video files, Erasure Coding still provides savings so the delta between Nutanix and HPE SVT will only increase in Nutanix favour the less the customer data will dedupe and/or compress.

HPE SVT on the other hand has a RAID (RAID 6 being N-2 usable or RAID 60 being N-4 usable) overhead and on top of that, use replication (2 copies / 50% usable) for an usable capacity (of raw) of well below 50% depending on the number of drives per node.

Nutanix, using RF2 and EC-X provides between 50% (minimum) and 80% (maximum) usable capacity of RAW and with RF3 (N+2) between 33% (minimum) and 66% (maximum) usable excluding the benefits of compression and deduplication.

The next major factor in data efficiency ratios is how they are measured!

In Part 1 I have already covered how misleading HPE SVT’s 10:1 efficiency guarantee is, and this is a great example of why it can be difficult to compare apples/apples between vendors. Nutanix on the other hand does not measure data efficiency in the same misleading manner.

In Summary:

  1. Nutanix AOS 5.1 has comprehensive data reduction/efficiency reporting within the PRISM HTML GUI
  2. Nutanix data reduction capabilities exceed that of HPE SVT as both products have Dedupe and Compression, but Erasure Coding (EC-X) is only supported on Nutanix
  3. All data reduction capabilities on Nutanix are complimentory, so Dedupe , Compression and Erasure Coding can all work together to maximise savings.
  4. Erasure Coding provides data reduction even for data which is not compressible or dedupeable
  5. Nutanix data efficiency stats are easily visible in the PRISM GUI and are much more detailed than HPE SVT

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But wait, there’s more!

As far as data reduction results are concerned, they are all over twitter and a simple search comes up with many examples. The first one being my favorite. Not because of the data reduction ratio itself but because it shows one of the major values of a 100% software solution where a simple software upgrade (which is one-click rolling, non-disruptive) provided the customer a significantly higher data reduction ratio. So basically, the customer got more capacity for free!

Note: None of the below show the latest data efficiency reporting capabilities from AOS 5.1.

Here are a few other examples which I found using this Twitter search:

Nutanix Dares2Compare with HPE Simplivity

The following is a list of claims made by HPE as part of the #HPEDare2Compare twitter campaign regarding Nutanix and a series of blog articles and Youtube videos which disprove these claims and highlight the value of the Nutanix platform.

Dare2Compare Part 1 : HPE/Simplivity’s 10:1 data reduction HyperGuarantee Explained

Dare2Compare Part 2 : HPE/Simplivity’s claim Nutanix snaps take 10x longer

Dare2Compare Part 3 : Nutanix can’t support Dedupe without 8vCPUs

Dare2Compare Part 4 : HPE provides superior resiliency than Nutanix?

Dare2Compare Part 5 : Nutanix can’t claim single screen management w/o extra fees or GUIs

Dare2Compare Part 6 : Nutanix data efficiency stats can’t be found

Dare2Compare Part 7 : HPE provides superior performance to Nutanix


More coming soon! Stay tuned!

Dare2Compare Part 3 : Nutanix can’t support Dedupe without 8vCPUs

As discussed in Part 1, we have proven HPE have made false claims about Nutanix snapshot capabilities as part of the #HPEDare2Compare twitter campaign.

In part 2, I explained how HPE/Simplivity’s 10:1 data reduction HyperGuarantee is nothing more than smoke and mirrors and that most vendors can provide the same if not greater efficiencies, even without hardware acceleration.

Now in part 3, I will respond to yet another false claim (below) that Nutanix cannot support dedupe without 8vCPUs.

This claim is interesting for a number of reasons.

1. There is no minimum or additional vCPU requirement for enabling deduplication.

The only additional CVM (Controller VM) requirement for enabling of deduplication is detailed in the Nutanix Portal (online documentation) which states:


There is no additional vCPU requirement for enabling cache or capacity deduplication.

I note that the maximum 32GB RAM requirement is well below the RAM requirements for the HPE SVT product which can exceed 100GB RAM per node.

2. Deduplication is part of our IO engine (stargate) which is limited in AOS to N-2 vCPUs.

In short, this means the maximum number of vCPUs that stargate can use of a 8vCPU CVM is 6. However, this 6 vCPUs is not just for dedupe, its to process all I/O and things like statistics for PRISM (our HTML 5 GUI). Depending on the workload, only a fraction of the maximum 6 vCPUs are used, allowing those cores to be used for other workloads. (Hey, this is virtualization after all)

Deduplication itself uses a small fraction of the N-2 CPU cores and this brings us to my next point which speaks to the efficiency of the Nutanix deduplication compared to other vendors like HPE SVT who brute force dedupe all data regardless of the ratio which is clearly inefficient.

3. Nutanix Controller VM (CVM) CPU usage depends on the workload and feature set being used.

This is a critical point, Nutanix has configurable data reduction at a per vDisk granularity, Meaning for workloads which do not have a dataset which provides significant (or any) savings from deduplication, it can be left disabled (default).

This ensures CVM resources are not wasted performing what I refer to as “brute force” data reduction on all data regardless of the benefits.

4. Nutanix actually has global deduplication which spans across all nodes within a cluster whereas HPE Simplivity deduplication is not truly global. HPE Simplivity does not form a cluster of nodes, the nodes act more like HA pairs for the virtual machines and the deduplication in simple terms in with one or a pair of HPE SVT nodes.

I’ve shown this where 4 copies of the same appliance are deployed across four HPE SVT nodes and the deduplication ratio is only 2.1:1, if the deduplication was global the rate would be closer to, if not 4:1 and this is what we see on Nutanix.

Nutanix can also have defined deduplication boundaries, so customers needing to seperate data for any reason (e.g.: Multi-tenancy / Compliance) can create two containers, both with deduplication enabled and enjoy global deduplication across the entire cluster without having customers refer to the same blocks.

5. Deduplication is vastly less valuable than vendors lead you to believe!

I can’t stress this point enough. Deduplication is a great technology and it works very well on many different platforms depending on the dataset.

But deduplication does not solve 99.9% of the challenges in the datacenter, and is one of the most overrated capabilities in storage.

Even if Nutanix did not support deduplication at all, it would not prevent all our existing and future customers achieving great business outcomes. If a vendor such as HPE SVT want to claim they have the best dedupe in the world, I don’t think anyone really cares, because even if it was true (which in my opinion it is not), then the value of Nutanix is so far beyond the basic storage functionality that we’re still far and away the market leader that deduplication it’s all but a moot point.

For more information about what the vCPUs assigned to the Nutanix CVM provide beyond storage functions, check out the following posts which addresses FUD from VMware about the CVMs overheads and the value the CVM provides much of which is unique to Nutanix.

Nutanix CVM/AHV & vSphere/VSAN overheads

Cost vs Reward for the Nutanix Controller VM (CVM)


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