Over the years we’ve written a lot in our blogs about the hardware upgrade subscriptions that are a part of Evergreen™ Storage — programs like Free Every Three and Upgrade Flex that keep your FlashArray controllers modern, and Capacity Consolidation that helps preserve your investment in flash media as you expand and modernize your arrays. These are key components of our Evergreen Gold subscription, and have helped customers adapt and respond to changing business and IT imperatives, while saving money by eliminating costly traditional forklift upgrades. These customer savings have contributed to Pure Storage’s Satmetrix-audited net promoter score (NPS) ratings being many times the industry average (currently Pure’s is at 83.7).

Like SaaS, Evergreen Storage just keeps getting better, without downtime or impacting performance.  From acquiring to managing to upgrading your storage, it delivers Evergreen value and peace of mind.  It’s a subscription to innovation, in your data center.

Like all successful visionaries that help change a market, we’ve seen our share of imitators, and the beneficiary has been you, the customer.  Many legacy storage vendors have been offering programs and promotions attempting to mimic what Pure offers. Of course, Pure’s storage products were engineered from the start to be Evergreen, and that’s not something that can be duplicated through a legacy storage vendor’s marketing or loyalty program.  So while none have come close to Evergreen Storage, at least the industry is now seeing some movement in the right direction from legacy vendors.

But that’s also why Pure never stops trying to innovate for our customers — and today is no exception, as we roll out an important update to our Right-Size Guarantee, a part of Evergreen Storage, extending its coverage and value to unparalleled lengths.

The Right-Size Guarantee solves a common pitfall customers can face when buying flash storage. Since storage vendors have sought for years to fit more data into less raw flash, there are many competing claims out there on how well each vendor delivers on this goal.  Pure has been a proven leader in this space since the early days of flash, with our investment in advanced data reduction technologies that are always-on and deliver results typically 2x better than other storage vendors (our global average total efficiency is 10:1). But customers could easily be caught on the horns of a flash sizing dilemma. On the one hand, they risk buying too little storage if a vendor’s data reduction or storage efficiency claims don’t match their reality, causing a scramble to add capacity that can impact both budgets and operations.  By contrast, they also risk being forced to buy too much storage, tying up precious resources and limiting their ability to respond to other IT imperatives.

Storage Sizing Basics

First, a quick diversion into what can be a tricky topic if you’ve never compared storage arrays before, and even if you have.  How exactly are arrays sized — and what do all these different terms like raw, usable, and effective mean?  Let’s start with the basics.  When a customer says they need a certain amount of storage, let’s say 200TB, they don’t necessarily go out and buy that much in flash (or even disk).  They do however tell a storage vendor that they need 200TB in effective capacity — i.e., the total space that an array will deliver to them while it’s running.  In the flash world, most arrays work backward from that effective capacity number to eventually determine how much actual (or raw) flash is needed to deliver it.  The basic formula is this: raw capacity, less system overhead (space needed for system software that delivers fancy storage features, RAID overhead, etc.), equals usable storage.  That usable storage amount is then multiplied by a data reduction ratio to deliver the total effective capacity.  So, in our example, for a legacy vendor it might look like this:

150TB Raw Capacity – 50TB System Overhead = 100TB Usable Capacity


100TB Usable Capacity x 2:1 Data Reduction Ratio = 200TB Effective Capacity

Now obviously if we increased that data reduction ratio, we’d wind up with more effective capacity.  If it’s 3:1, we’d get 300TB effective — but more importantly, since we don’t really need the extra capacity right now, we could reduce the amount of raw flash needed by 33% to 100TB (from 150TB), thus lowering our acquisition costs, while still delivering us the 200TB we need.

So, that data reduction ratio is key — it drives efficiency and potentially lowers our initial acquisition costs.  But what if we don’t actually get the 3:1 ratio that was promised?  Well, then we’ll run out of space for our needs.  If we buy based on 3:1 but only get 2:1, we’ll be short on our capacity by 33%.  Ouch.

Pure Guarantees the Right Size

Enter Pure’s Right-Size Guarantee, first introduced in 2016 with Pure’s expanded Evergreen Storage program.  The Right-Size Guarantee shifted the customer’s sizing risk at first purchase onto Pure, by guaranteeing them not simply a data reduction value — but guaranteeing instead a minimum amount of effective storage that is sure to meet their needs.  Because, in the end, the sizing question customers care about most is:  Will I have enough storage for all of my data?  With the Right-Size Guarantee, customers get guaranteed effective capacity that ensures that they are buying just the amount of storage they need, when they need it. Customers avoid the twin risks of buying too little storage and scrambling to add capacity later, or buying too much and wasting precious resources.

How does the Right-Size Guarantee work? First, Pure works with the customer to gather their effective capacity requirements by workload – any workload. The more we know, the more accurate (and efficient) the configuration we can offer. Behind the scenes, we derive expected data reductions by workload from our global installed base using the Pure1® array management system.  Based on the real-world data from Pure1 showing how Pure FlashArrays are actually performing in the field, we can predict the data reduction and total efficiency ratios that specific workloads will get.  We then apply those ratios to a customer’s effective capacity requirements, thus generating an efficient, right-sized configuration backed by a guaranteed effective capacity number.

With Pure’s Right-Size Guarantee, customers are free to focus on their effective capacity and applications, and Pure takes care of the rest. If a customer’s FlashArray does not deliver on the promised effective capacity as they migrate their data over the six-month period of the guarantee, we will make it right – which includes providing free additional flash, as-needed, to meet the written guarantee. And, we’ll do it non-disruptively. With the Right-Size Guarantee, customers get the storage they need, and never have to worry about buying an undersized (or oversized) array. The Right-Size Guarantee is available in both the Evergreen Gold and Silver subscriptions.

Now, Extend the Benefits!

The peace of mind that the Right-Size Guarantee affords can now be extended indefinitely, up to the life of the array – which in Pure’s case with our Evergreen technology and non-disruptive upgrades, just keeps going and going.

Any capacity expansion purchase can now trigger a new Right-Size Guarantee, which extends coverage for another 6 months on the new total capacity and workload mix.  This new feature is a perfect fit for the way that many Pure customers use (and love) their Pure storage.  Once customers see how truly effortless and Evergreen their FlashArrays are, and how easy they are to expand non-disruptively, they just keep adding more and more workloads to them. Since every expansion purchase can be covered by a new Right-Size Guarantee, and combined with the fact that most organizations grow their data by 20% or more annually, Pure customers’ protection and peace of mind can be extended throughout the life of their arrays.  No other storage vendor offers a capacity guarantee that is so simple yet so comprehensive and long lasting.

Beware of the Imitators

The imitation game that we mentioned earlier has played out in this space, too. Every storage vendor is naturally trying to show their own technology in the best light possible, especially when trying to compete with Pure’s industry-leading data reduction and total efficiency.  As a result, technologies are added into vendors’ numbers which might technically be considered storage efficiencies, but have little bearing on true data reduction or delivering more effective storage to customers.  Examples of these are snapshot savings, thin provisioning and RAID tiering. Customers can be forgiven if they’re confused by the endless claims from storage vendors of their efficiency or data reduction ratios — and by the different kinds of guarantees offered to try and imitate Pure’s Right-Size Guarantee.  Most (if not all) of these guarantees focus solely on the claimed ratio — efficiency, data reduction, or some other term — that he customer will see.  And that’s all that’s guaranteed in those cases, not the resulting effective storage. In addition, most of these guarantees are strictly time-bound, offered for a limited time, or not extendable.

That’s again why Pure’s Right-Size Guarantee focuses on the effective capacity a customer is looking for.  And our data reduction relies solely upon proven methods, such as deduplication and data compression, since these are the only methods that actually reduce the amount of raw storage needed — and therefore, are the methods that should be used in sizing an array.  The result?  With Pure, we make things simpler and more transparent for customers. There’s already enough confusion out there: Am I buying enough?  Are these vendors really comparable in their claims?  Who’s numbers can I trust?  With Pure, it’s simple, and it’s Evergreen.


Engineered to be Evergreen

What does it mean when Pure says its products are engineered to be Evergreen?  What separates Evergreen Storage from other vendor programs is the remarkable engineering behind it.  Pure Storage designs its arrays to enable fully modular, non-disruptive upgrades, including components that other vendors cannot upgrade like the backplane, that make technology refresh simple, easy, and low-risk – even across generations.  Such FlashArray upgrades do not even require planned downtime, whether for software or hardware. This design offers independent performance and capacity upgrades, allows flash device geometries to be mixed in the same system for maximum configuration flexibility, and supports simple in-place data migration during capacity consolidation operations.

The key to Pure’s Right-SIze Guarantee lies in Pure’s more efficient, multi-stage, always-on storage efficiency deduplication and compression technologies.  These drive the higher data reduction ratios that Pure Storage achieves relative to legacy storage vendors, and were what initially drove those legacy vendors to have to include other features besides just compression and deduplication in their “data reduction storage efficiency ratio” calculations.  These are features that are difficult for them to build into their systems, even over time.  Legacy storage technology often comes with a legacy of compromises, especially in the all-flash world.

In order to further reduce confusion and help customers make more informed comparisons, Pure is including thin provisioning (something that many legacy storage vendors use in their own efficiency claims) in our total efficiency ratios.  We include that total efficiency number in the Right-Size Guarantee right alongside our data reduction ratios, and of course the customer’s guaranteed effective capacity. Pure’s global average total efficiency rate is greater than 10:1, which is about double our average data reduction rate of 5:1 — and still 2x that of the average competitor’s efficiency claims.  Now, customers can make more informed comparisons between Pure and other vendors.

But most importantly, with the Right-Size Guarantee, customers will have the peace of mind that they’ll have the right amount of storage for their needs, even as they expand and grow.  Guaranteed.

Want more information on Evergreen Storage and the Right-Size Guarantee?  Check out our Evergreen Storage and Evergreen Subscriptions pages on, and download the IDC white paper on Evergreen.  And keep checking back on our blogs, as we keep the conversation going on Evergreen Storage, how it saves customers money, and how it delivers the flexibility and agility needed for today’s IT organizations.