DELL EMC CX4 EXCHANGE PERFORMANCE THE ADVANTAGES OF DEPLOYING DELL/EMC CX4 STORAGE IN MICROSOFT EXCHANGE ENVIRONMENTS Dell Inc. October 2008 Visit www.dell.com/emc for more information on Dell/EMC Storage. Copyright 2008 Dell Inc. THIS WHITE PAPER IS FOR INFORMA- TIONAL PURPOSES ONLY, AND MAY CONTAIN TYPOGRAPHICAL ER- RORS AND TECHNICAL INACCURACIES. THE CONTENT IS PROVIDED AS IS, WITHOUT EXPRESS OR IMPLIED WARRANTIES OF ANY KIND.
CONTENTS EXECUTIVE SUMMARY 3 INTRODUCTION 3 CX4 IN MICROSOFT EXCHANGE ENVIRONMENTS 3 ULTRAFLEX I/O MODULES 3 iscsi 3 Direct-attach Storage (DAS) 3 ENHANCED CACHE MANAGEMENT 4 DISASTER RECOVERY 4 VMWARE INTEGRATION 4 CX4 PERFORMANCE ADVANTAGE 5 MICROSOFT EXCHANGE SIMULATION WORKLOAD 5 CONCLUSION 6 APPENDIX: MICROSOFT EXCHANGE TEST ENVIRONMENT 7 MICROSOFT EXCHANGE SIMULATION 7 TESTING METHODOLOGY 7 TABLE 1: COMPETITIVE WORKLOAD SUMMARY 5 FIGURE 1: CX4-240 TO COMPETITION MS EXCHANGE SIMULATION 5
EXECUTIVE SUMMARY Dell/EMC CX4 storage systems with UltraFlex technology can help to offer distinct advantages when deployed in Microsoft Exchange environments. UltraFlex technology offers increased connectivity flexibility. Enhanced cache management on the new CX4 sustains high performance levels even under degraded conditions. Integration with VMware offers new functionality and expanded ease-of-use features. A performance comparison between the Dell/EMC CX4-240, IBM DS4800-88, and HP EVA8100 clearly illustrates the CX4 s competitive edge when compared against similar arrays. When pitted against these two arrays, the CX4 series offers up to an 18 percent advantage in mail system performance. In addition, the CX4-240 exceeds or equals the raw storage capacity of its competition. Dell/EMC CX4 offers unparalleled flexibility, a robust feature set, and competitive performance leadership, making it an ideal storage system for deployment in Microsoft Exchange environments. INTRODUCTION This white paper will take a high-level look at the features and functionality that make the CX4 an excellent choice for Microsoft Exchange and other electronic mail systems. We will begin by examining new features like UltraFlex I/O modules and enhanced cache management. Then we will move to a discussion of disaster recovery and VMware integration, which are critical metrics by which customers evaluate storage systems. Finally, we will conclude with a brief example of CX4 s performance advantage in Exchange environments. CX4 IN MICROSOFT EXCHANGE ENVIRONMENTS ULTRAFLEX I/O MODULES The CX4 takes a fresh approach to array connectivity. UltraFlex technology provides Exchange users the ability to configure their CX4 to match their server environment. CX4 arrays are configured with UltraFlex I/O modules to connect to Fibre Channel (FC) servers, iscsi servers, or both. Not only can the CX4 connectivity be customized from the factory, it can be expanded postinstallation as well. Adding FC or iscsi ports in the field is a non-disruptive process. This capability makes the CX4 hardware future-ready. As newer and faster technologies are developed and come to market, CX4 series arrays will be able to implement them. Dell has already announced two examples of this, 8Gb/s FC and 10Gb/s iscsi. Other vendors require a storage refresh to utilize this technology. A simple I/O module upgrade is all that is necessary to implement the latest and greatest connectivity technology with CX4 series storage arrays. iscsi Every model in the CX4 line-up supports both FC and iscsi front-end connectivity. Using CX4 s 1Gb/s Ethernet-based iscsi can provide acceptable performance at a lower cost, making it a good choice for many small and medium-size deployments. Many competitors midrange arrays do not provide iscsi front-end ports built into the array. They require purchasing and maintaining FC-toiSCSI protocol converters. The CX4 can support four to 16 iscsi ports on a single system. The CX4-240 array benchmarked in this whitepaper supports up to 12 iscsi ports. Direct-attach storage (DAS) Multiple Exchange servers can be connected to a CX4 without the need for a FC or Ethernet switch. While other arrays can do this, the CX4 enables many options for front-end ports per storage array. With UltraFlex technology, these ports can be tailored to exactly what the user needs, not a one size fits all distribution like other storage arrays on the market. 3
The CX4 makes growing an infrastructure easy. Users can start with a DAS deployment. Then, as the requirements grow, the infrastructure can easily be migrated into a larger SAN topology. ENHANCED CACHE MANAGEMENT CX4 builds on the proven reliability and high availability delivered by the CX3 series. CX4 introduces improvements that focus on maximizing performance during maintenance activities. One of the most significant improvements surrounds how the write cache maintains operation on the CX4 storage system when, for example, a fault occurs to a redundant subsystem such as a power supply. Improved cache availability will translate directly into sustained levels of high performance. When write cache is disabled, performance is negatively impacted. Therefore, to ensure the highest levels of performance at all times, the write cache should be disabled only when absolutely necessary. Advances in both the hardware and software of the CX4 afford it this capability. A single component fault within the storage system will not disable the write cache. These enhancements to cache management and upgrades to the Navisphere Service Taskbar (NST) have made the already straightforward FLARE upgrade process even simpler. DISASTER RECOVERY Few applications are as integral to everyday business as e-mail. E-mail has become the de facto communications standard in corporate environments. This can be attributed to its ability to reach many geographically dispersed individuals quickly, and because it maintains a written record of all exchanges. For these reasons and more, Microsoft Exchange is a mission-critical application for many customers. They simply cannot afford to lose e-mail due to site unavailability or disaster. Replicating Exchange data to remote sites ensures that this business-critical application remains available at all times. Dell/EMC CX4 has built-in technology to address these replication needs. Optional EMC MirrorView, EMC SAN Copy, and EMC RecoverPoint fill out a robust portfolio of replication technologies specifically designed for the CX line. Each of these solutions approaches replication from a slightly different angle. With this breadth of choices, customers can balance their recovery point objectives (RPO) and recovery time objectives (RTO) with cost considerations. Furthermore, CX4 enables remote replication using both FC and iscsi. This broad offering of replication technologies, over multiple protocols, ensures that CX4 can help solve your storage challenges. VMWARE INTEGRATION Exchange deployments in VMware environments require advanced automation and ease-of-use features. CX4 meets this requirement with support for advanced tools like VMware Site Recovery Manager (SRM), VMware Distributed Resource Scheduler (DRS), and Navisphere Quality of Service Manager (NQM). The Navisphere Service Taskbar's proprietary high availability verification tool (HAVT) can now analyze VMware deployments. Ultimately, many customers choose to implement their VMware Exchange environment on Dell/ EMC CX storage because of its proven track record. CX4 hardware and software are built upon the tenets that made the previous generation of CX extremely reliable and available. Proven availability combined with excellent performance make CX4 the excellent choice for VMware Exchange deployments. 4
CX4 PERFORMANCE ADVANTAGE Performance is a key metric by which every storage system must be measured. CX4 outperforms the competition in Exchange deployments. Better performance means more users can be supported more efficiently with a single storage asset. The following table summarizes the storage system capacity and application performance between the model CX4-240 and competing systems. From the table, you can see the CX4 series offers an almost 18 percent higher performance advantage in mail system performance over its closest competitor. In addition, the CX4-240 exceeds or equals the raw storage capacity of its competition. Table 1. Competitive workload summary IBM DS4800-88 HP EVA8100 Dell/EMC CX4-240 MS Exchange simulation (# users) 23,950 23,542 28,235 Maximum hard drives 224 240 240 The mail system load used in this comparison may not be identical to your workload. However, it is comparable to a real production environment. And, it can be used to compare the relative performance of the Dell/EMC CX4 with competitive storage systems under the same conditions using the characteristic Exchange I/O pattern. MICROSOFT EXCHANGE SIMULATION WORKLOAD The following figure compares the Microsoft Exchange simulated workload performance of the CX4-240 model and the competition storage systems found in this comparison. Figure 1. CX4-240 to competition MS Exchange simulation workload comparison 5
From the figure you can see the CX4-240 has a performance advantage over the similarly sized competition. The CX4-240 outperforms both the HP EVA8100 and IBM DS4800-88 in the mail system simulation. CONCLUSION In an Exchange performance evaluation between the CX4-240 and its closest competition the HP EVA8100 and IBM DS4800-88 CX4 outperforms the competition. Enhancements to cache management help ensure that this high level of performance is sustained at all times. A robust portfolio of disaster recovery technologies protects data across geographies. UltraFlex I/O modules offer the flexibility to align your environment to meet your needs. These features, combined with world-class performance, make it easy to see why Dell/EMC CX4 is an excellent storage choice for Microsoft Exchange. 6
APPENDIX Our comparison focuses on storage system performance in a mail system environment. This production environment is representative of a typical environment used by midrange storage systems. MICROSOFT EXCHANGE SIMULATION The Microsoft Exchange workload simulates the small-block random I/O patterns characteristic of Microsoft Exchange and Microsoft s LoadSim applications. The workload consists of small-block random reads and writes in at a ratio of 2:1. The Microsoft Exchange simulated workload generates randomly distributed reads and writes to 50 percent of the configured storage using concurrent threads. Within each thread, a subsequent random read or write is started as soon as the previous I/O completes. This creates one parallel I/O per thread. The metrics for this test is I/Os Per Second (IOPS) and Exchange Users. The IOPS are determined first. IOPS are used to calculate the number of Exchange Users the target array supports assuming the storage system is configured to run at 80 percent of its Microsoft Exchange IOPS rating with the average Exchange User performing one I/O per second. TESTING METHODOLOGY For the testing, EMC made every effort to configure each storage system to obtain optimal performance for the workload and provide as fair a comparison as possible. For example, all tests were executed with the same number and type of server and the servers were monitored to ensure they were not adversely affecting the test. Identical host bus adapters (HBAs) where used. And published best practices from each of the storage system manufacturers were followed. All systems were as closely configured hardware-wise as their manufacturer allowed. For example, they were all configured using 4Gb/s Fibre Channel attachments, with their maximum number of 146 GB 15k rpm hard drives configured as RAID 5 or VRAID 5 RAID groups of the same size. The Workload approach simulates a storage system s performance in a production environment. We believe this is a better way of comparing storage system performance than simpler benchmarks. It avoids the synthetic raw performance and possibly misleading results of benchmark programs. For example, benchmarks typically only exercise one aspect of a system, such as frontend ports. Or they may generate unnatural, extremely high IOPS (short access pattern) or high bandwidth (long access pattern), behavior that would normally set off alarms in a production environment. The Workload approach exercises both the front-end host connections and the back-end interface to the hard drives, and generates more natural I/O patterns. It generates I/O appropriate to the system s configuration, typically determined by the number of hard drives. In addition, it sustains the workload over a long period of time to determine the longer-term behavior of the storage system s hardware and software. The Dell/EMC CX4 series offers performance options spanning from an entry-level CX4-120 to an enterprise-level CX4-960. The CX4-240, with its up to 16 front-end ports, two redundant back-end buses, 8 GB of RAM, and two dual-core CPUs, is in the middle of the CX4 series range. 7