Hybrid Storage

Achieve a better balance with hybrid storage

Data is growing at a rate of over 100% per year. The challenge for organisations is to maintain storage capacity and performance whilst managing costs, saving space and considering the environmental impact of their solution.

For the last 20 years, there has been little in the way of innovation concerning storage. The capacity of drives has been getting bigger, but the limits imposed by the mechanics of hard disk drives has prevented any real improvement in performance.

Every time a user logs on and loads a file, there is input/output activity as the data moves in or out of storage. The growth in data and increasing variety of types of data is demanding more in terms input/output performance.

All-Flash arrays

In recent years, solid state drives have become more prominent in the storage industry, resulting in many organisations deploying storage arrays made up entirely of flash memory. These offer less capacity than a traditional array, but massive performance, with IOPS reaching around 100,000. As SSDs have less capacity than HDDs, flash memory uses data reduction technologies such as compression and deduplication to combat space issues.

However, there are a number of challenges with all-flash arrays. Firstly, many organisations may not really need the levels of performance on offer, and actually the balance offered by hybrid would be better suited. They are also much more expensive than both traditional and hybrid solutions, with the initial costs of acquisition reaching 6 figures.

Enter hybrid storage

Hybrid storage is the perfect balance between capacity and performance. Only in very recent months has this technology been applied to servers and it’s set to revolutionise the way organisations store and access their data.

What is hybrid storage?

Hybrid arrays are made up of a mixture of HDDs and flash memory. The flash memory often acts as a sort of ‘super cache’, where the most accessed files are stored. The server’s operating system monitors which files are accessed most often over time and creates a workload to move files from the HDDs to the SSDs. This allows for fast log-in and boot times. Below is an illustration of how a hybrid storage solutions works:

Why go hybrid?

As we mentioned, traditional storage arrays are made up of hard disk drives which offer high capacity, but pretty low performance. The performance for HDDs hit a ceiling of 15k RPM, offering at most 200 IOPS (Inputs/Outputs per Second). HDDs are also mechanical, meaning they are susceptible to wear and tear over time. With an SSD, there are no moving parts, meaning they last longer and are much more reliable. SSDs are also currently capable of over 6000 IOPS, a figure which is growing exponentially.

Hybrid arrays offer much better performance than a full HDD array, use less power and less space. Some are also fitted with smaller power supplies, using less energy. They offer a perfect balance between capacity and performance, and as hybrid arrays are becoming more common, they are no longer unachievable in terms of cost.


Flash memory is changing the face of an industry that’s been largely at a standstill for nearly 20 years. With lower cost for massive performance benefits, without losing the capacity offered by traditional storage arrays, it’s clear that hybrid is the way to go.


Table source: http://www.techrepublic.com/blog/data-center/the-brewing-battle-between-hybrid-and-all-flash-storage/