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The state of all-flash versus hybrid storage in Australia and New Zealand

Magnetic disk drives are yesterday’s technology. Soon all servers will be based on all-flash arrays – or will they?

Spinning a thin disk of magnetic material at thousands of revolutions per minute while holding delicate, microscopic read/write elements a few microns above each platter’s surface to detect and modify the magnetic polarity of infinitesimally small dipoles to store and retrieve data…

The conventional hard drive is a bizarre invention when you really think about it. There’s so much that could go wrong, from the heads crashing into the disk surface to the magnetised bits losing – or even flipping – their orientation.

Yet the spinning-disk hard drive has formed the backbone of the IT revolution for decades, and it is only in the past few years that it has begun to lose ground to solid-state storage.

Currently, the most common server configuration is a hybrid one, with spinning disks for capacity topped off with flash-based storage for performance and caching.

But as solid-state storage gets cheaper, surely spinning disks will eventually spin their last and grind to a halt? I spoke to analysts from Gartner and Frost & Sullivan to find out how the battle is progressing.

High cost of SSDs prolong life of HDDs

The Australia and New Zealand region is a microcosm of the global market. It is nothing special in terms of solid-state and hybrid storage – neither far ahead of the rest of the world nor far behind it. That, at least, makes the numbers easier to find and understand.

Gartner predicts year-on-year enterprise data storage growth requirements of 35%, which will take some filling. You might think that most of those new server drives would be all-flash, but you’d be wrong.

Going by Gartner’s figures, the ratio of conventional hard disk drives (HDDs) to solid-state disks (SSDs) in terms of total storage capacity was 16.9:1 in 2014 and an estimated 15.9:1 in 2015. For 2016, the estimate is 13.1:1.

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So, on an equal capacity basis, that is more than 13 conventional hard disk drives required by enterprises in 2016 for every single SSD. The gap is closing, but even with SSDs entering what Gartner calls the “cost phase” (market maturity) in 2016, there is some way to go.

In fact, cost is still the big issue for enterprises. More accurately, cost per gigabyte (or terabyte – pick your preferred unit). SSDs have all sorts of benefits, such as low noise, fast access, low power consumption and high shock tolerance, but they have a long way to go to match the price per gigabyte of spinning disks, which is why hybrid configurations remain popular.

Lynda Stadtmueller, vice-president of cloud computing services at Frost & Sullivan, also sees cost as a major factor. “Flash is a superior storage technology,” she says. “It’s faster, more reliable and delivers higher performance than traditional hard disks.

“It is also more expensive [although prices are dropping]. So buyers face a price-performance choice when they add storage or replace ageing storage systems.

The rumours of HDD’s demise partake of a stupefying quantity of hype
John Monroe, Gartner

“Not all workloads require superior storage, and, in most cases, it wouldn’t be cost-effective for a company to choose a gold-plated, all-flash solution for all its storage.”

Another recent Gartner storage report agrees, predicting: “HDD and SSD technology will continue to have a profound effect on external controller-based [ECB] storage systems. HDD technology will evolve to its strengths, which are increasing capacity while reducing cost per gigabyte.

SSD technology will push the frontiers of performance, raw capacity expansion, cost reduction and reliability improvement. As SSD technology matures, HDD technology will continue to be used to store persistent data with little to no activity, or to support streaming data applications characterised by sequential access patterns.”

Behind this maturing technology are some well-known names. Samsung, Intel, Sandisk, Micron and Toshiba lead the development of SSD internals, the Nand chips that store all the data. It is in their interest to increase production as quickly as possible, and as they do so, costs will inevitably drop.

The chart below shows that ECB storage platforms composed of HDDs only or SSDs and HDDs (hybrid) remain the largest segment from a revenue perspective, with all-flash SSD systems steadily gaining a bigger share of the ECB storage market.

Gartner analyst John Monroe is quite blunt about the prospects of spinning platter hard drives dying out any time soon. “The rumours of HDD’s demise partake of a stupefying quantity of hype,” he says.

In his view, high-capacity SSDs will continue to be relatively expensive on a dollar-per-gigabyte basis, but will become increasingly efficient in delivering value on a dollar-per-transaction and TCO basis.

“The greatest opportunities for deployment are in highly virtualised environments that will include [but not be limited to] cloud datacentres; database, data warehousing and high-performance computing environments; and hosted virtual desktop infrastructure [HVDI] environments,” he says.

Hybrid storage offers best of both worlds

So firms in Australia and New Zealand, like those elsewhere, have the best of both worlds. They can choose high-capacity spinning disks for most of their data, adding SSDs for high-performance data transfer whenever required.

There is something to fit every budget, and that budget stretches ever further as SSDs fall in price and HDDs rise in capacity.

As Frost & Sullivan’s Stadtmueller says: “Every business probably has a combination of traditional HDD and flash storage in its datacentre. Hybrid storage solutions provide centralised management and visibility across integrated components. This is why hybrid storage solutions that support both HDD and SDD storage are a preferred alternative to either traditional HDD or all-flash.

Hybrid storage solutions provide centralised management and visibility across integrated components. This is why hybrid storage solutions are a preferred alternative to either traditional HDD or all-flash
Lynda Stadtmueller, Frost & Sullivan

“The best hybrid solutions allow businesses to allocate media and capacity optimally across workloads, with common management and reporting tools.”

Eventually, it seems likely that spinning disks will die out, but – like floppy drives in the late 1990s – they will take their time about it. In fact, they may take even longer than floppy drives, because there is another niche that might suit vast, relatively slow but cheap hard drives quite well – as a replacement for tape archives. Those spinning magnetic platters will be with us for a few years yet.

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