A glimpse into the future

This article is part of a series examining the value of tape in the era of cloud and object storage. In my last few posts, I considered the compelling benefits that emerge for tape when considered over longer periods of time than just a few years. In this post, I want to look at tape’s technology advantage in relation to areal density and what we know about the innovation curve for advanced magnetic media recording using LTO Ultrium or hard disk drives. One of the reasons why I am optimistic about the future of tape is because the technology has a powerful and credible innovation roadmap that seems better matched to the challenge of colossal digital data growth.

Data isn’t vapour

Fundamental to this discussion is the simple fact that data isn’t a gas. It takes up space.

Regardless of platform, it has to be stored on something. The cloud isn’t a cloud. It’s a lot of hardware joined together by wires and controlled by software. It’s very clever technology. But it’s still physical. It still has presence. And it’s that presence that creates a set of practical challenges for today’s storage technologies.

Flash is high performance data protection. It does things that tape devices weren’t designed for. But it isn’t economical or durable enough for large scale archiving spanning decades.

And hard disks are approaching the threshold of how small you can make the magnetic particles coating the disk whilst retaining their effectiveness. This is typically characterised by two phenomenon: spontaneous data decay and difficulties with writing at high data rates.

To record more data in a given area using magnetic media like disk or tape, you need to make the space occupied by each bit smaller. That means you need smaller magnetic particles with which to coat the disk to maintain a good signal to noise ratio.

The problem is that it becomes more challenging to reduce the size of the particles without compromising their ability to maintain a magnetic state in a stable way. As particles are squeezed closer together, their individual magnetic fields begin to blur. This causes data corruption and data loss. The point at which the particles are too small to be viable is known as the superparamagnetic limit. Hard disk manufacturers have begun to push up against this threshold which is why the new Heat- Assisted Magnetic Recording (HAMR) and Microwave-Assisted Magnetic Recording (MAMR) drives now being developed are far, far below the 100 TB capacities once assumed for the early years of the next decade.

How tape is opening up new frontiers

In fact, according to INSIC projections, by 2025 we may see HDDs of 40 TB in capacity, which is only about 20% CAGR in areal density from today’s products.

However ‘limitless’ the cloud may appear, therefore, any disk-based storage system will inevitably have to confront the reality that scaling pools of hard drives in object storage in the zettabyte era will need colossal quantities of devices, energy, floorspace and resource.

And none of those things come without strings attached. The world’s data centres already use more power than Spain. Already some newer data centres are being built with their very own solar energy source and I have even heard of studies exploring the feasibility of building underwater data centres powered by wave energy from above. So if it’s possible to reduce energy demands by using a cheaper and fundamentally more energy efficient solution, like tape, this has to be a consideration to evaluate against the perceived benefits of using disk.

And in terms of areal density, tape still has plenty of headroom. LTO-12 is targeting 480 TB per cartridge in roughly the same time frame of the next ten years. That’s around 33% CAGR in areal density - about double the projection for disk drives.

It’s important to realise that any disk-based array or object storage server using magnetic media technologies like HAMR or MAMR will be governed by the superparamagnetic limit. So for storing trillions of gigabytes of unstructured data in the very near future, tape is the ideal, cost effective long term solution. It has the support of leading vendors, it requires almost no energy at rest, it has a reliable roadmap and it’s already being used by millions of businesses.

Don’t get me wrong: the new HAMR and MAMR drives being developed by leading HDD vendors will be vitally important for the future of our digital universe. For the applications that require them - and there will be many - they will undoubtedly be deployed in colossal data warehouses like some of the gigantic installations being planned by cloud providers like Microsoft or Amazon. And those data centres will, over time, be powered by renewable energy sources which will mitigate the environmental impact of hyperscale storage and computing. For example, earlier this year Google announced it would install 1.6 million solar panels, equivalent to 300MW of power, to supply energy to two new data centres in the south eastern United States.

But if data is growing at 30-40% a year and disk capacity is only achieving 15% per year, then there is a fundamental mismatch between supply and demand. And the gap between those numbers is where I expect tape to come into its own as the most practical and cost effective solution for preserving infrequently accessed cold data for many years, even decades. The question is not ‘why would you consider using tape?’, but ‘why would you not consider use tape?’