Solid State Drives (SSDs) offer a number of advantages over traditional hard disk drives (HDDs). With no seek time or rotational delays, SSDs can deliver substantially better I/O performance than HDDs. Capable of driving tens of thousands of I/O operations per second (IOPS), as opposed to hundreds for HDDs, SSDs break through performance bottlenecks of I/O-bound applications. Applications that require dozens and dozens of "extra" HDDs for performance can meet their I/O performance requirements with far fewer SSDs, resulting in energy, space, and cost savings.
Solid State Drive technology was introduced more than three decades ago. Until recently, however, the high cost-per-gigabyte and limited capacity of SSDs restricted deployment of these drives to niche markets or military applications. Recent advances in SSD technology and economies of scale have driven down the cost of SSDs, making them a viable storage option for many I/O intensive enterprise applications.
While the cost of SSDs is trending downward, the $/GB for SSDs is still substantially higher than that of HDDs. Thus, it is not yet cost-effective for most applications to replace all HDDs with SSDs. Fortunately, it is often not necessary to replace all HDDs with SSDs. For instance, infrequently accessed (cold) data can reside on lower cost HDDs while frequently accessed (hot) data can be moved to SSDs for maximum performance. Many applications have a high percentage of cold data compared to hot data allowing SSD usage to be leveraged very effectively. The appropriate mix of SSDs and HDDs is then used to strike a proper balance between performance and cost.
To demonstrate the benefits of SSDs, we ran experiments comparing SSDs with HDDs. The experiments showed a significant performance advantage with SSDs which resulted in a substantial reduction in the number of drives needed to meet the desired level of performance. Fewer drives translate into a smaller physical footprint, reduced energy consumption, and less hardware to maintain. The experiments also showed better application response times for SSDs, which leads to increased productivity and higher customer satisfaction.
This paper focuses on applications in an IBM i operating system environment. Other papers are available for other IBM environments. IBM i 5.4 and IBM i 6.1 offer some very powerful functions that can allow you to easily, productively and cost effectively implement SSD in your environment. The paper describes how to deploy SSDs in a tiered storage environment to allow you to leverage your existing storage with SSDs for maximum performance and minimum cost. This paper also discusses IBM i tools and services available to assist you in deploying and managing a storage solution with SSDs.
The integrated Storage Management capability of IBM i 5.4 and 6.1 has added new SSD function to the existing ASP Balancer allowing "hot" data to be easily identified and placed on SSDs. It also leverages the increased speed of SSDs by automatically placing specific system-critical, high-use objects on these faster drives. Additionally, a new "media preference" option has been created as part of an integrated solution with DB2 and Libraries.