StorPool: The traditional SAN is dead. Arise, software-defined multi-controller block storage

Interview StorPool CEO Boyan Ivanov and his team see their block storage access software, running on multiple controllers, as an example of the “post-SAN” storage that’s needed in an environment that they believe has moved on from the invention.

SANs (Storage Area Networks) were developed from the mid-nineties onwards as a way of giving server-based applications a way to access more storage than an individual server could usefully manage and as a way to provide a shared pool of block storage for many servers. It was and still is a popular and widely used on-premises IT technology, but newer ways of providing block-level storage are claimed to solve problems which limit SANs.

Boyan Ivanov.

We asked Storpool CEO Boyan Ivanov a set of emailed questions about the problems he thinks beset SANs and what alternatives exist for SAN users.

Blocks & Files: How is it that the SAN concept, developed in the ’90s, is not working now?

Boyan Ivanov: The SAN concept was developed as a way to provide shared storage capabilities to applications, so it abstracts the data from a single physical device or host/server. This was a way to provide reliability and data longevity, regardless of hardware failures, and to consolidate data silos. 

This was a good approach, but the design dates back to a time when business demands from applications and the size of IT were rather small. You may say minuscule by the workloads and business needs of today. There used to be tens of servers connected to a single SAN storage array. There are still many cases where the SAN approach makes sense and is very good. Typically this is the case when the size of the IT systems is small, or less complex and demanding. 

However, most applications of today require a very different approach. One is they operate on a much, much larger scale, which makes using specialized, single-purpose storage arrays (i.e. SANs or all-flash arrays, AFA) unfit. Today’s data centers have tens of thousands of servers, all needing extremely fast access to the storage system. So we need a new way of thinking about data storage. 

Also end users today want always-on, blazingly fast applications. Businesses need to deliver these at lower and lower budgets and in increasingly more complex and unpredictable environments. The demands for agility, performance, uptime, operational efficiency, and cost optimizations simply cannot be met by the storage array architecture. 

We need a new approach and a storage architecture designed for the demands of this century going forward, not for the last one. 

Blocks & Files: Can you summarize the problems?

Boyan Ivanov: The old approach to storage has so many issues. 

The traditional SAN, which is a dual-controller, shared disk system is just too inflexible. What happens if six months after you install your building block, you realize you need lower latency or higher capacity? How do you do that without breaking up your building blocks?

Modern businesses operate in the always-on operating model. There are no maintenance windows. Applications work 24×7. Provisioning, scaling, etc. need to happen within that model. This is not how traditional/legacy SANs and flash arrays operate. 

Controllers often become performance bottlenecks, which are difficult to address. Adding to the rigidity of the solution. 

Large-scale (multi-rack) availability is difficult to manage in traditional arrays. For example, taking several racks down to address a power issue would be a major project requiring synchronous replication with a SAN solution. 

There are high-cost system lifecycles and misaligned lifecycles between storage and servers. 

Traditional storage arrays generally have slow adoption of innovation compared to industry-standard servers. The latest networking and CPU and high-speed DRAM and media always appear first on commodity servers. 

Traditional SAN arrays are difficult to manage at scale. You always end up with multiple silos to take care of. 

SAN/AFA (All-Flash Array) storage systems were built with the idea of being managed by a graphical interface (GUI) by hand, by highly-trained storage administrators. And users of today need a self-service, API-driven storage that they do not log into. It’s integrated into their IT software stack. Customers don’t want to be buried in service tickets for every minor provisioning change – they need self-service and dynamic provisioning so there’s no service interruption. 

Blocks & Files: Can the SAN concept be improved?

Boyan Ivanov: The short answer is no, and we’ve written about why a while ago. 

To give it an analogy – it is impossible to turn a ship into an airplane when you need cargo transported from one place on Earth to another. They are both storage and transportation appliances, yet the architecture and utility are very different. They intersect on a small area of cases and are fit for different purposes, use cases, and ways of running a business.

In more practical terms – while the now legacy storage paradigm gets improved – faster drives, bigger controllers and interconnects – it is still handicapped by its architecture, developed in the 1990s. We need a radical departure from this approach. 

Blocks & Files: If the SAN concept has run out of road where do we go from here?

Boyan Ivanov: As the famous statement from Marc Andreessen goes “software is eating the world”. 

We are moving away from a hardware-centric approach to a software-centric one. The value is (and has always been in the software). Standard hardware, managed by smart software is so much more flexible, agile, faster, and cost-efficient. 

It is a fluid, multi-controller system, based on standard servers, running applications as well as storage. It’s programmable, flexible, integrated, and always on. It is scalable online, both in terms of capacity and performance. It makes hardware lifecycle management, forklift upgrades, maintenance windows, and downtime a thing of the past. 

It is the way of the future for most modern IT workloads and teams and increasingly so for traditional workloads like databases and core applications, which now operate at a much larger scale. 

And much of the component innovation that everyone focuses on is just a building block for a software-centric architecture. NVMe devices. Checked. NVMeOF/TCP. Checked. CXL. Checked. DNA storage – likely so, too. Quantum storage anyone?

Blocks & Files: Do you think that we need a new approach to data storage?

Boyan Ivanov: It is not that we do. It is the current state of the world that imposes one on us.

The requirements for speed, flexibility, and cost efficiency that each IT infrastructure team is facing are not being addressed with the architecture of the last century. 

As a result, there is a lot of extra work and workarounds that IT teams now do and take for granted, while end users just struggle. 

Without going down the rabbit hole, just a few examples: 

  • Performance does not scale, separately from capacity – if you do not get the needed performance – get one more box. Now you have data silos and more boxes to manage
  • Waiting for months or years, to get the latest technologies, at a humongous price
  • Downtime on upgrades, refresh cycles, scheduling maintenance windows
  • Performance degradation of the solution, as you fill it up
  • Applications choking for performance, leading to application & database splitting & sharding. And so complexity and cost explode. 
  • Vendor lock-in and price hikes or dead-end streets, when a SAN line gets discontinued. 

All these are not sustainable anymore and create missed opportunities, cost millions of dollars, and squander human potential. This is why we need a new approach to running mission-critical applications and managing their most important primary data. 

Blocks & Files: Dell, NetApp, IBM, Infinidat and others would say the SAN concept is healthy. How are they mistaken?

Boyan Ivanov: You cannot get a radically different outcome by doing incremental improvements to the existing technology. 

The SSD was not an improved HDD. It was a new concept, made possible at a certain stage of technical progress. It was a quantum leap. 

Note that these technologies co-exist today. Companies are deploying more HDD capacity compared to 10 years back when we barely had SSDs. However, now every core application is using NVMes. 

So there is nothing wrong with SANs and AFAs. They are here to stay and will be used for certain use cases. But the bulk of the workloads, the important things, are switching to software-centric storage. 

For example, how many SANs are Amazon or Google using for their EBS and persistent disk services? Zero right? It’s an insane question to ask. At their scale they have figured out this is not done by a hardware appliance, it’s software. 

And out of all rudimentary implementations of storage software, StorPool is the most advanced, yet proven block-storage data platform on the market. It is giving the missing building block to customers, running diverse and demanding workloads at scale. We built this because we saw how the world is changing and what users need, not what is still the thing that is sold the most, but on the slide. 

Blocks & Files: What do you recommend and why?

Boyan Ivanov: We recommend that people reevaluate how they think about storage. It is not a hardware appliance anymore. It is fluid, it’s software-driven. 

Further data storage is not a single component anymore. To start with, current IT environments are very interconnected – compute, networking, and storage are becoming one integral system, more tightly coupled. 

The impact of a next-generation storage platform is unlocking value across the board.

From more obvious things, like reduced datacenter footprint, less energy consumption, and fewer man-years spent on repetitive manual tasks. To unexpected gains – much faster applications, faster time to value, new high-value services, less employee time wasted on unproductive work, and more done by the team for the same amount of time. Then you have reductions in TCO as faster storage can optimize compute and networking costs, as our customer Namecheap found it can get up to 60 percent savings on compute resources. So a next-gen storage solution can ease staffing shortages and improve employee happiness while optimizing the cost structure and profit margins of the entire business. 

In practice: we recommend that people start their datacenter design with their storage requirements. Making the wrong decision around storage is so expensive in the long run. It’s not just the cost and hassle of upgrading or replacing a mistake. It’s living with the mistake. Living with poor application performance harms all phases of your business. Lost customers because of slow transactions. Lost productivity due to slow queries. Lost business opportunities because your team is fussing with their storage solution instead of investing in growing their business.

When we talk with prospects, they are aware of the points and limitations of traditional SAN architecture. They just don’t know that they have better choices. So my advice to them is to demand better.