The Value of Shared SSDs in Enterprise Computing QLogic Mt. Rainier Integrates SSDs with SAN Connectivity Key Findings Mt. Rainier technology from QLogic is a PCIe -based intelligent I/O accelerator that provides integrated storage-network connectivity, solid-state disk (SSD) interfaces, and embedded processing required to make SSD management and caching tasks entirely transparent to the host. QLogic Mt. Rainier technology delivers: Caching offload to adapter hardware to deliver I/O acceleration. Shared caching for clustered, virtualized, and distributed workloads across the data center. Simple deployment by means of a single driver and management model that reduces software stack complexity.
Executive Summary With Mt. Rainier Accelerator technology, QLogic delivers a unique solution set that is optimized to address the growing performance gap between what today s processors can compute and what the storage I/O subsystem can deliver. This approach seamlessly combines enterprise server I/O connectivity with shared, server-based I/O caching. Mt. Rainier uses industry-standard SSDs to deliver dramatic and smoothly scalable application performance improvements to the widest range of enterprise applications. Over the last several years, SSDs have proven to be a key differentiator for server performance. Because the price of industry-standard SSDs has also dropped over the last few years, the convergence of low-cost Flash and its improved performance has only benefited single-server performance. Today s virtualized and distributed workloads across the data center also demand faster I/O access. Existing solutions do not address the added dimension of multiple servers acting together to run complex business-critical applications, such as online transaction processing (OLTP), online analytical processing (OLAP), and other clustered compute environments such as Oracle ERP Analytics and Web 2.0. This white paper covers the advantages provided by the QLogic Mt. Rainier Accelerator technology. It also guides the reader toward making informed decisions when considering the value of Flash memory in the form of SSDs to enhance server performance. Introduction Storage I/O is the primary performance bottleneck for most virtualized and data-intensive applications. While processor and memory performance have grown in step with Moore s Law (doubling in chip performance every 18 months), storage performance (spinning media) has lagged far behind. Over the past two decades, data storage delivery performance has proven problematic for enterprise storage administrators. Recent challenges are poised to severely constrain infrastructure capabilities in the face of increasing virtualization, consolidation, and data analytics. While data density and compute horsepower have increased almost logarithmically over the years, storage performance improvements remain comparatively sluggish. A new class of server-based storage acceleration is the latest innovation in the market to address this performance disparity. The idea is simple: fast, reliable, solid-state Flash memory connected to the server yields faster data access to the server s CPU. Flash memory, in the form of SSD media, is readily available in the market and promises to perform much faster than any rotational disk under typical, small, highly random, I/O enterprise workloads. Yet adoption of this technology in the enterprise is lagging: 79 percent of these applications are clustered, virtualized, and require shared data. An Industry First Mt. Rainier technology from QLogic provides I/O acceleration across the storage network. Mt. Rainier technology is a PCIe-based, intelligent, I/O processor that provides integrated storage network (Host Bus Adapter) connectivity, SSD interfaces, and the embedded processing required to make SSD management and caching tasks entirely transparent to the host. Built on the QLogic core Host Bus Adapter and storage routing technology that is hardened and proven in the enterprise, QLogic has created an accelerator that not only uses industry-standard SSDs to speed up server I/O access, but also uniquely allows servers to share access to cache SSD storage. Today s enterprise applications demand faster I/O access because they are clustered and virtualized, and have distributed workloads across the data center. Mt. Rainier uniquely addresses these needs by providing shared cached data, accelerator clustering to maintain cache coherence, high availability, and optimal allocation of cache resources. The implementation at the Host Bus Adapter level also simplifies the installation and management of server-based SSD caching. Mt. Rainier can identify what data should be cached through awareness of the I/O across the storage area network. Because Mt. Rainier recognizes the contents of all Mt. Rainier caches across physical servers, cache and SSD management is transparent to the servers. In addition, the only host-resident software required for Mt. Rainier operation is a host operating system (OS)-specific driver all heavy lifting is performed onboard the Mt. Rainier by the embedded multicore processor. SSG-WP12003B SN0430912-00 Rev. B 11/12 2
Mt. Rainier delivers what other SSD caching solutions cannot. These other direct-attach, captive cache solutions fall short because: Caches cannot be shared between servers that are running clustered or virtualized applications. Where each server has a captive cache, cache coherency between servers cannot exist. Software complexity increases due to the addition of filter drivers and applications consuming precious CPU cycles. Caching breaks data protection and compliance policies of the SAN. Caching Offload to Adapter Hardware The QLogic Mt. Rainier controls all caching and SSD management in the adapter hardware, acting just like a standard Host Bus Adapter in the server. This control results in an application-transparent and infrastructureand storage subsystem-agnostic solution. The QLogic solution delivers the application performance acceleration benefits of server-based cache, without the limitations of solutions that require separate, server-based storage management software and OS filter drivers. The QLogic Mt. Rainier caching offload enables faster application response time, provides lower latencies for data access, and results in increased productivity. Mt. Rainier delivers: More transactions per second. Increased virtual machine count per server. Faster response from data analysis. Increased business growth and profitability. By delivering full hardware offload, QLogic adapters provide significant performance benefits, and remove the need for large memory footprints required to create mapping between data that is cached and data that remains in the SAN. This ability conserves server memory for applications and services, and it maximizes server virtualization ratios. Because Mt. Rainier contains Host Bus Adapter functionality, it is fully aware of the read/write I/O traffic on the Fibre Channel link. This awareness enables Mt. Rainier to make data caching decisions based on throughput traffic patterns, thereby optimizing data access for all the applications running on a server. Shared Caching Between Mt. Rainier and Servers The QLogic Mt. Rainier accelerator delivers something that no other SSD caching solution has today: the ability to cluster Mt. Rainier accelerators and the cache between servers. Clustering Mt. Rainiers creates a logical group that provides a single point-of-management, and cooperates to maintain cache coherence, high availability, and optimally allocate cache resources. Unlike standard Host Bus Adapters, Mt. Rainier accelerators communicate with each other using the Fibre Channel infrastructure. This communication allows the cluster to manage caches across multiple server nodes. After administrators define caches for specific LUNs on the SAN, each Mt. Rainier accelerator can identify the owner of the cache. Because all Mt. Rainiers recognize the cache owner for a specific data LUN, I/Os are redirected to the cache owner. This distributed cache model enables a single copy of cache data, which also maximizes the use of SSDs and makes it more scalable. LUN cache ownership guarantees that at any time, only one Mt. Rainier is actively caching any specified LUN. Any member of a Mt. Rainier cluster that requires access to a LUN that is cached by another cluster member redirects the I/O to the specific LUN s cache owner. As shown in Figure 1, the I/O of Server 1 uses the cache on Server 2. Figure 1. Managed LUN Cache Ownership Figure 2 shows that the QLogic Mt. Rainier shared cache brings scalable performance to clustered and virtualized applications, without adding complexity. This value is realized in: VMware, Microsoft Hyper-V, Citrix, and Kernel-based Virtual Machine (KVM) environments where caches remain warm when moving virtual machines across servers. Clusters such as Oracle Real Application Clusters (RAC), IBM DB2 purescale, and Microsoft Windows Server Failover Clustering (WSFC) with SQL or Exchange servers. Shared cache models that support clustered and virtualized applications. Distributed cache that enables highly scalable architectures. SSG-WP12003B SN0430912-00 Rev. B 11/12 3
Figure 2. Shared Cache Pedigree and Technology Deployment Built on the QLogic core Host Bus Adapter and storage routing technology, Mt. Rainier uses the QLogic Fibre Channel driver and management stack, as shown in Figure 3. The QLogic Mt. Rainier software model provides: A mature driver stack with years of robust OS and application interoperability. One standard driver required (by OS). No additional server resources. Simple and standard installation, management, and maintenance that result in lower operating costs. In contrast, other SSD caching solutions management and cache control reside in the host and OS. This arrangement creates additional complexity, increases OS dependencies, and consumes additional server resources, as identified previously in Figure 3. Managing additional drivers, agents, and applications creates unnecessary complexity in real-world configurations, which also increases operating costs and headaches within the IT infrastructure. Overall, these other solutions create: The need for more drivers OS dependencies Interoperability issues Increased use of server resources Increased complexity, which equates to higher operational costs Figure 3. Mt. Rainier Software Stack Uses a Single Driver This model greatly simplifies deployment of Mt. Rainier, as compared to software-based caching and SSD solutions. Because the hardware provides all of the SSD and cache management, each OS requires only a standard Fibre Channel driver. The driver uses the QLogic QConvergeConsole utility and a CLI as management tools for cache and SSD data LUN creation, as well as typical Fibre Channel device management. SSG-WP12003B SN0430912-00 Rev. B 11/12 4
Summary and Conclusions Increased server performance, higher virtual machine density, advances in network bandwidth, and more demanding business application workloads are creating a critical I/O performance imbalance between servers, networks, and storage subsystems. The QLogic Mt. Rainier accelerator technology provides a reliable and efficient architecture that delivers the key value of shared Flash in enterprise computing, by enabling adoption of Flash SSD and caching for I/O-intensive servers. The QLogic Mt. Rainier provides integrated storage network (Host Bus Adapter) connectivity, SSD interfaces, and the embedded processing required to make SSD management and caching tasks entirely transparent to the host. This combination unleashes SSD caching performance for a broader set of enterprise applications, including clusters and multiserver virtualized environments. These platforms strain each server s I/O and take advantage of industry-standard SSD technology, which is key to closing the storage performance gap between faster servers demanding more I/O and conventional disk drives not keeping pace. The QLogic Mt. Rainier delivers in these key areas: Caching Offload. Offload results in a transparent, OS-independent, and infrastructure-agnostic solution that delivers the application performance acceleration benefits of server-based SSDs. Caching offload does not have the limitations of solutions that require separate server-based storage management software and OS filter drivers. Shared Caching. Mt. Rainier delivers the ability to cluster accelerators and share cache between servers. Clustering Mt. Rainiers creates a logical group that provides a single point-of-management and cooperates to maintain cache coherence and high availability, as well as to optimally allocate cache resources. Simpler Software. The accelerator uses the QLogic Fibre Channel driver and management stack, which is enhanced to support the caching and data LUN capabilities of Mt. Rainier. Because all SSD and cache management is provided within the hardware, Mt. Rainier requires only a standard Fibre Channel driver for each OS. These benefits of the QLogic Mt. Rainier technology enable efficient and cost-effective pooling of SSD cache resources among servers. Implementing the QLogic Mt. Rainier technology unleashes the performance of SSDs with enterprise applications applications that are clustered and virtualized and provides faster application response time that results in increased productivity and an improved customer experience. SSG-WP12003B SN0430912-00 Rev. B 11/12 5
Disclaimer Reasonable efforts have been made to ensure the validity and accuracy of these performance tests. QLogic Corporation is not liable for any error in this published white paper or the results thereof. Variation in results may be a result of change in configuration or in the environment. QLogic specifically disclaims any warranty, expressed or implied, relating to the test results and their accuracy, analysis, completeness or quality. Follow us: Share: Corporate Headquarters QLogic Corporation 26650 Aliso Viejo Parkway Aliso Viejo, CA 92656 949-389-6000 www.qlogic.com International Offices UK Ireland Germany France India Japan China Hong Kong Singapore Taiwan 2012 QLogic Corporation. Specifications are subject to change without notice. All rights reserved worldwide. QLogic, the QLogic logo, and QConvergeConsole are registered trademarks of QLogic Corporation. Citrix is a registered trademark of Citrix Systems, Inc. IBM, DB2, and purescale are trademarks or registered trademark of International Business Machines Corporation. Microsoft, Windows, and Hyper-V are registered trademarks of Microsoft Corporation. Oracle is a registered trademark of Oracle Corporation. PCIe is a registered trademark of PCI-SIG Corporation. VMware is a registered trademarks of VMware, Inc. All other brand and product names are trademarks or registered trademarks of their respective owners. Information supplied by QLogic Corporation is believed to be accurate and reliable. QLogic Corporation assumes no responsibility for any errors in this brochure. QLogic Corporation reserves the right, without notice, to make changes in product design or specifications. SSG-WP12003B SN0430912-00 Rev. B 11/12 6