The Role of Flash Storage in the Private Cloud

The performance requirements of cloud computing environments are stretching the physical limits of traditional rotating hard disk drives (HDDs). Because rotating HDDs rely upon mechanical operations to perform their tasks, they are running up against limitations in handling the random input/output operations-per-second (IOPS) demanded by highly virtualized production environments, of which cloud computing is a leading example.

As companies are putting more and more of their mission-critical applications into private cloud infrastructures, they are coming to the realization that they must do something to upgrade the performance of their storage solutions, particularly when it comes to delivering required IOPS for tier one production environments. Fortunately, the availability and affordability of enterprise-grade solid-state storage solutions is enabling companies to deliver the speed and overall performance demanded of private clouds.

While solid-state storage has been around for a long time, it is only in recent years that the price of enterprise-grade flash has come down to the point where it is affordable in comparison to HDD storage solutions. Flash is still far more expensive on a cost-per-gigabyte measure, which means it is not the solution you would be looking to utilize for backup, archiving or disaster recovery activities within your private cloud.

However, when you look at flash on a cost-per-IOPS basis, it is certainly competitive with HDDs and in some cases may even be more cost efficient. More important, it delivers performance that HDDs simply can’t match. For those applications that demand the highest levels of IOPS performance in the private cloud—think online transaction processing and/or e-commerce, for example—flash is really the only way to go. The questions for IT decision makers coalesce around what to look for in a flash solution. Here are some of the key issues to think about:

  • All flash or a hybrid array: IT decision makers have options in using either all-flash arrays or hybrid solutions that combine flash with HDD drives. An all-flash array will typically cost more but deliver greater overall performance. A hybrid array will typically use intelligent tiering to allocate storage based on the performance requirements of the application. In deciding on one or the other, you should look at the performance requirements of your targeted applications and how they are growing.
  • Resiliency: You are probably running multiple applications in the private cloud, so you want to make sure your flash storage solution never experiences downtime, planned or unplanned. That means it must have a management platform that doesn’t require planned downtime for maintenance. You also want a flash solution that minimizes overall performance degradation in the event of the failure of any single drive within a cluster. The other important resiliency issue with flash is the endurance of the medium. Flash storage will only support a finite number of writes during its lifecycle, so you want to consider solutions that minimize writes and maximize the life span of the drives.
  • Integration with existing infrastructure: Whichever storage platform you choose for flash, you want to make sure that it integrates well with your existing environment. If you’re like most companies, you will use flash in the private cloud for tier one production environments, so you will want to make sure the flash solution integrates well with your backup, archiving and disaster recovery environments. You will also want to look at the architecture of the flash solution. A scale-out architecture will give you elastic scalability, which is important in the cloud, but it may require moving away from your existing scale-up infrastructure.

If you’re moving applications into the private cloud and you haven’t come up against bottlenecks caused by slow I/O performance of HDDs, then you’ve been very lucky—so far. In most cloud environments it’s just a matter of time before enterprises will need to incorporate flash at some level in order to deliver on the performance demanded by highly virtualized cloud environments. When you examine potential flash solutions make sure to keep in mind the three issues discussed here: All flash versus hybrid, resiliency and integration with existing platforms.

© 2014 Intel Inc.