top of page

What is CI? What is HCI? - Why FlashStack? FlashStack vs. HCI solutions

[ NOTE: machine translation with the help of DeepL translator without additional proofreading and spell checking ]

Hyper-converged is the future, they say. But why? Is that true at all? As I have found out time and again, there are many different opinions and views when it comes to choosing the right data center hardware. Hyper-Converged Infrastructure is still a relatively new approach, but it has already established and proven itself in the market.

Today's digital markets are more unpredictable than ever before. Data growth is exploding and businesses are constantly changing. Companies need infrastructure platforms that not only optimize costs, but also provide the maximum flexibility. They need infrastructure that responds to needs flexibly, transparently and quickly. To cope with increasing demands from data legislation that requires more data to be stored securely and retained for longer. Add to that new operations and modernized applications that require the highest data center standards.

“Virtualization, service orientation, and the Internet have converged to sponsor a phenomenon that enables individuals and businesses to choose how they'll acquire or deliver IT services, with reduced emphasis on the constraints of traditional software and hardware licensing models.” - Chris Howard (Research Vice President at Gartner)

Hyper-Converged Infrastructure (HCI) is defined as follows: a software-based IT infrastructure with integrated data storage, network and computing power/compute that is integrated into the standard hardware offered by a vendor.

In HCI solutions, SAN/NAS silos are replaced by software-defined storage systems. The traditional components required to operate SAN/NAS storage are simultaneously consolidated into an enclosure to form an appliance. This appliance then acts practically like a Direct Attached Storage (DAS) and provides its storage in the form of virtual pools. HCI combines computing power (processors and RAM) with mass storage (SSDs and hard disks) in each individual (virtual) machine, but combines the storage of multiple machines with storage software into a unified system. This facilitates management and automation under a unified administration interface.

Quelle: Nutanix

A Converged Infrastructure (CI) unifies data center components into one appliance that can be managed in a centralized manner. The goal of a Converged Infrastructure is to reduce compatibility problems and simplify the management of servers, storage systems and network devices. Converged Infrastructure is also sometimes referred to as Unified Computing, Data Center-In-A-Box or Infrastructure-In-A-Box. CI products can be from a single vendor or sold as a collaboration between multiple verified vendors.

Quelle: HostAdvice

As you can see, HCI is a CI solution with an "on-top software" ... so the statement like "a brand new technology" of the newfangled storage hipsters is rather relative in my eyes. ツ

Goals and motivation

What I see, however, is that both solution approaches pursue completely different goals or involve very different motivations and motives.

With converged infrastructure, the goals are:

  • adaptable performance

  • massive scalability

this with management of all CI infrastructure components.

With hyperconvergence, on the other hand:

  • facilitate scaling of workload environments

  • remove complexity from administration

  • Create automation

HCI is completely "controlled" from one interface with integrated hypervisors.

Without exception, the basis of HCI solutions is always an Ethernet network, on which everything depends and to which every HCI node must be connected.

CI vs. HCI

In my opinion, the main shortcoming of HCI is definitely its non-variable scalability. If a user needs additional storage capacity, for example, he has to add complete HCI nodes, including servers and network components, depending on the provider. This increases the costs, but the basic idea of the solution makes this necessary.

Source: NetApp Blog

In addition, an HCI stack brings with it an increased risk of failure and potential danger in the event of software problems! A software error or security gap in the kernel/software stack can quickly lead to total failure of the complete system. Likewise, data inconsistency can occur in the event of problems in the network. With CI, this risk does not exist if the network and FC-SAN are strictly separated.

The Nutanix Enterprise Cloud platform is the leading solution in the HCI space and it while it is aimed to deliver great business outcomes and minimise CAPEX,OPEX and TCO, the platform is not designed to be “cheap”. - Josh Odgers - A TCO Analysis of Pure FlashStack & Nutanix Enterprise Cloud

read more regarding this statement @ :

CI consists of building blocks. Each of the components in one of these building blocks is discrete and can be used individually for its intended purpose and, unlike most HCI, provide the ability to expand or replace individual components. In other words, the server, for example, can be used separately and strictly as a server. In contrast, with HCI, the technology is software-defined. The entire technology is fully integrated, so it cannot be broken down into individual components.

For example, with a CI system, a user needs a larger all-flash storage array. In this case, the user can replace the array with one with more storage without buying new servers and network components at the same time.

The fact that compute and storage capacity requirements do not increase in lockstep is particularly common in the so-called "systems of record" that form the backbone of a data center. A CI makes it possible to react granularly to changing demands on such systems. This is easy on the IT budget.

There are also two other factors: firstly, IT specialists can adapt the system components of a CI, such as servers from Fujitsu/DELL EMC/HPE and storage systems from Pure Storage, to the requirements of individual applications. Such fine-tuning is usually only possible under restrictions with an HCI. This is quite intentional, because it simplifies the configuration and operation of the appliances.

On the other hand, a convergent infrastructure system can be implemented in conjunction with a virtualization layer or on the "bare" hardware (bare metal). IT specialists thus have more options with a CI than with an HCI, but they must also have greater expertise.

Another shortcoming is that existing storage systems can only be connected to a hyperconverged system with effort. The reason is the tight integration of the components of an HCI appliance. This high degree of integration can also lead to dependence on a single system supplier.

When does HCI make sense?

  • Reduction of operating costs and increase of employee productivity

  • Optimized deployment, support and management

  • Minimization of IT components. All IT services and infrastructure are consolidated below the hypervisor into a single, shared pool of x86 resources

  • centralized management of virtual environments worldwide through a single interface

When does CI make sense?

  • For deploying new tier-one applications or virtualizing applications.

  • When managing remote or branch offices or ROBO, infrastructures.

  • for remote disaster recovery sites

  • For data center consolidations, whether within or between data centers.

  • For virtual desktop infrastructures or VDIs

  • Performing frequent data migrations within or between sites

  • Testing or developing infrastructures

  • Multi-hypervisor environments

A CI solution - the Pure Storage FlashStack

FlashStack, a converged infrastructure solution from Cisco and Pure Storage, unlocks the power and efficiency of all-flash storage for your entire Cisco UCS-based data center. Using industry-leading components from Cisco and Pure Storage, FlashStack is a powerful and robust converged infrastructure solution. It scales without disrupting operations as your business grows, delivering the speed and reliability of all-flash for every workload.

FlashStack consists of Cisco MDS Fabric and Nexus switches, Cisco UCS Fabric interconnects, Cisco UCS Server. Pure Storage FlashArray and or Pure Storage FlashBlade systems.

Management is possible with various software: Cisco UCS Central, Cisco UCS Director, Cisco ONE Enterprise Cloud. In addition, various Cisco technology tools can be used to automate configurations on the fly.


INFO: FlashStack does not have to be purchased as a complete solution! If you already own Cisco infrastructure components, they can be added/used to a FlashStack. Means: with existing UCSes, FEXes, Nexus only Pure Storage Arrays would have to be added. After that, a fully validated FlashStack solution would be flying.


FlashStack Solution Overview | Source: Pure Storage

The advantages of FlashStack

Significantly lower costs

FlashStack includes computing, networking, and management from Cisco with Pure Storage to help reduce capital and operating expenses.


FlashStack is easy to acquire, operate, and upgrade. You can deploy flexible services as needed while keeping costs low. Proven, validated interoperability and for secure application delivery.


Achieve the always-on performance you need to support today's critical workloads and build your private cloud.

Always up to date

Easily scale and grow along with your business. Install once, and upgrade indefinitely with no disruption.

"Harmony" and support

Pure Storage FlashStack is co-developed with Cisco to get maximum performance and reliability from both vendor solutions. Support is provided by Cisco from a single source - a one-stop support contact for all your CI issues.

Deep Dive - look inside

Start Small and Grow Easily with FlashStack

"Get in touch" with FlashStack hardware and components. Have first touches with a few imaginable system configurations.

FlashStack Mini | Source: Pure Storage

FlashStack In Sight | Source: Pure Storage

FlashStack Scaling | Source: Pure Storage

FlashStack Lösungen | Source: Pure Storage

Pure Storage FlashStack 360° Tour: take a look

For more information, the Cisco Pure Storage whitepaper can be downloaded here.

More info - Links

All officially published setting options in the GUI but also CLI can be read via the "on-board" user guides of the Pure Storage systems.

Click on "Help" in the Purity main menu.

The User Guide is structured like the main menu and can be opened downwards. A search function is also integrated - within here you can also search for keywords.

WEB: Pure Storage (Pure1) support portal - Ticket system and support *(requires registered FlashSystems)

PHONE: Pure Storage phone support: GER - (+49) (0)800 7239467; INTERNATIONAL - (+1) 650 7294088

WEB: Pure Storage community

WEB: Pure Storage OFFICIAL blog

The blog lives from your questions, wishes and suggestions...every comment is welcome. I am very grateful for feedback.

291 views0 comments
bottom of page