What is Hybrid Storage?

What Is Hybrid Storage?

Hybrid storage describes storage systems that are designed with a blend of flash-based solid-state drives (SSDs) and mechanical hard-disk drives (HDDs) in an effort to provide high performance at an affordable price. 

From its benefits to how it matches up with other storage options, this guide provides everything you need to know about hybrid storage.

HDDs vs. SDDs

HDDs use magnetically coated, rapidly rotating disks for persistent data storage. Typical HDD performance falls within the range of 55-180 IOPS. SSDs use semiconductor cells to store data persistently. Also known as flash memory, SSDs are significantly faster than HDDs, with performance in the range of 3,000-40,000 IOPS.

For decades, mechanical HDDs have been the most common form of data storage for everything from home computers to enterprise-level direct-attached storage (DAS) devices, network-attached storage (NAS) devices, and storage area networks (SANs). 

While SSDs have been around for a long time, cost has been the primary factor slowing widespread adoption. The decision between HDDs and SSDs has traditionally been one of balancing cost with performance.

What are Solid-state Hybrid Drives? (SSHDs)

SSHDs combine the traditional magnetic drives of HDDs with the flash memory of SSDs into a single drive. The idea is to offset the cost of flash memory by relying on an HDD to meet capacity requirements.

SSHDs are also less complicated to manage than installing both an HDD and an SSD within the same system. Hybrid drives monitor data as it’s being read from the hard drive and cache the most accessed pieces of data in the NAND flash memory. Any data stored on the SSD will be served much faster, meaning your most essential files and applications will have SSD-levels of performance.

As the system learns the user’s behavior, the data that’s stored on the SSD will change over time. If certain files or data increase in usage, it will switch out other data for use by the SSD. When you first install an SSHD, you most likely won’t see a performance improvement. The drive takes time to learn the user’s behavior.

Hybrid Storage vs. SSD

So how do SSHDs stack up against SSDs? Because SSDs have superior read and write times than HDDs, SSHDs will always be limited by their HDD components. For the data that doesn’t get prioritized by flash memory, performance will only be that of an HDD.

Why Use Pure All-flash Arrays vs. Hybrid Flash Arrays?

At the enterprise level, the benefits of these various storage options can be scaled up and defined as an “array.” Many of the same principles from the data storage applications above apply. To summarize:

All-flash arrays use non-volatile, flash-only SSDs for data storage. With no moving parts and data that wouldn’t be affected by a power outage, they provide the best performance for an organisation’s data centre. 

While IT managers may have previously been concerned about the cost of using an all-flash system, the price of high-capacity SSDs is coming down steadily. In return, you get a reduced form factor, faster access to data, and employee-critical applications, while also producing less heat and using less electricity.  

Hybrid flash arrays use a mixture of HDDs and SSDs to provide a boost in performance compared to that of a traditional HDD array. Adding a small number of SSDs to make a hybrid storage array will provide a performance increase over HDDs alone. The SSDs work to move frequently accessed data into the faster flash memory. 

There are concerns about hybrid storage, including access speed and latency, as well as fears about security, compliance, and data portability. There is no substitute for the performance an all-flash array can provide.

Pure Storage® offers higher performance, capacity, and agility at a lower cost than hybrid storage and HDDs. All-flash arrays (AFAs) are not only revolutionising storage with cloud-like application, consolidation, and agility, they’re also usually the more economical choice. Check out FlashArray//C to see how Pure delivers hybrid economics with SSD performance.