Sizing guide for SAP and VMware ESX Server running on HP ProLiant x86-64 platforms

Transcription

1 Sizing guide for SAP and VMware ESX Server running on HP ProLiant x86-64 platforms Executive summary... 2 Server virtualization overview... 2 Solution definition...2 SAP architecture... 2 VMware... 3 Virtual machines and SAP... 3 Basis for sizing... 4 SD benchmark... 4 SAPS... 4 Sizing considerations... 4 Design guidelines...5 Sizing methodology... 6 Sizing individual virtual machines... 6 Multi-environment sizing... 7 Storage... 8 Networking... 8 Virtual machine sizing... 8 VM process sizing... 8 VM memory sizing... 8 VM network... 9 VM storage... 9 Extra hardware...9 Sample configuration... 9 For more information... 10

2 Executive summary Server virtualization overview Server virtualization is a set of emerging technologies that can potentially help businesses utilize idle computing power. The goal of this technology is to provide infrastructure management through tools that allow IT managers the ability to manage virtual machines. Traditionally, SAP has run on dedicated servers. Recently, SAP announced full support of VMware ESX Server for use with SAP ERP solutions. One area where these environments can take advantage of this technology is by running components of the SAP landscape within a virtual machine. For example, a customer builds a test-and-development system within a single virtual machine host. That single virtual machine can be copied, creating two separate test-and-development environments. The customer can execute tests on one virtual machine while continuing development within the second virtual machine. The configuration provides two completely separate SAP systems within a single hardware base, allowing system administrators the advantage of utilizing the hardware power available with current HP server platforms. This document presents a set of guidelines for sizing HP ProLiant x86-64 servers for use with virtualization of SAP solutions using VMware Infrastructure 3. Target audience: This document is intended for systems engineers working with customers to develop an SAP landscape. The landscape is expected to include multiple virtual machines supporting several components in a typical SAP environment. Solution definition SAP provides enterprise software applications designed to support business solutions. SAP solutions include multiple applications designed to increase access to business processes and information within a company. To support the various SAP business suites and solutions, SAP products are architected to support a multi-tier architecture. SAP architecture The basic architecture of the SAP suite of applications supports multi-tier deployment architecture. This multi-tier architecture supports a database, application and presentation tier. At the user level, there is the presentation tier. This is the layer represented by the GUI or web interface into SAP. At the middle layer, there is the SAP application server. The application servers run the business application. The third tier is represented by the database layer. Typical SAP ERP deployments are characterized by multiple servers at each layer. With the growth in server processing power these servers may provide unutilized processing power. With VMware virtualization technology, these servers are able to provide businesses with more effective use of resources. The majority of the processing within the SAP three-tier configuration is done at the application and database layers. Although one can use virtualization technologies at the presentation layer, the information in this document is focused on sizing of the application and database tiers. 2

3 Figure 1. Tiers in SAP architecture Two Tier Central System Three Tier USERS APPLICATION Layer Online Online Online Batch Batch Batch Online Process Batch Process DATABASE Layer Online Batch Database Database Database Processes VMware The VMware Infrastructure 3 suite of software virtualizes processors, memory, storage and networking. This presents a set of resources to allow multiple operating environments access to the resources needed. The use of multiple operating environments on the same server platform allows more efficient usage of hardware resources. The VMware products discussed here consists of: VMware Virtual Machine File System (VMFS): the file system that supports the storage of the virtual machines Virtual SMP: the symmetric multiprocessing (SMP) support allowing multiple virtual processors and machines to run on one HP ProLiant server VMware VirtualCenter: software for managing and deploying virtual machines VMware Infrastructure (VI) Client: software allowing access to a particular virtual machine display Virtual machines and SAP A single server running ESX Server allows virtualization of multiple SAP environments or layers of the architecture. A two-tier SAP system used for development or testing can be supported within a single virtual machine. Application servers could also be supported within multiple virtual machines. Virtualization of the SAP landscape and architecture provides customers a flexible solution to their computing requirements. 3

4 Basis for sizing SD benchmark The standard method used to determine workloads for sizing is through the use of the SAP Sales and Distribution (SD) benchmark. Over the past 10 years, SAP s hardware partners have executed the SD benchmark to understand the SAP requirements for sizing hardware. The results of the native SD benchmark state the number of users running on the system, a response time less than 2.0 seconds and the throughput of the system represented in SAPS. Table 1. Example data from the SD benchmark results ( Date SD Users Response Time (in seconds) Dialog Steps per Hour SAPS HP Server Platform Certification 9/3/ ,112,000 18,530 ProLiant DL580 G /3/ ,000 10,530 ProLiant BL685c /7/ , ,080, ,000 HP Integrity Superdome HP executed the SAP SD benchmark within a virtual machine running SAP ERP 6.0. This benchmark characterizes the performance of a single virtual machine. That information is used to understand the capabilities of a single two-processor virtual machine. From that information, the HP sizing tools and engineers are able to help customers find the appropriate hardware to support their IT environments. HP executed the SAP SD benchmark using ESX Server 3.5 and the ProLiant DL580 G5 server. The test environment consisted of two virtual processors and 12GB virtual memory. This configuration demonstrated excellent performance on the two-tier SAP SD benchmark with a result of 516 SD users, 2597 SAPs (results as of 3/14/2008 certification ). SAPS Overall SAPS are represented as: 100 SAPS = 2,000 fully processed order line items/hour or = 6,000 dialog steps and 2,000 postings or = 2,400 SAP transactions or = 20 SD benchmark users measured in SD Benchmark 1 SD benchmark 2sec = 5 SAPS Sizing considerations To develop a sizing, the first consideration is the expected number of virtual machines planned for a particular server. Through the use of virtualization technologies, it is possible to create environments for each layer within an SAP architecture. The customer scenario may consist of virtual machines to support separate test and development systems. There may be a need to support SAP application servers in addition to a standalone database server. Before sizing begins, a thorough understanding of the customer requirements and potential virtual machines must be obtained. 4

5 Each virtual machine estimate is based on the number of concurrent users or SAPS expected within a particular virtual machine. The SAP Quick Sizer provides sizing estimates based on this information. This is typically the first step in sizing. Although this is the typical method of sizing, the actual workload from a particular user varies. SAP user-based sizing models define three kinds of active users: Figure 2. Three types of active SAP users Concurrent active user: 1 low user or info-user, occasional user creates about 1/12 of a medium user 1 medium user creates about 35 transact./h 120 dialogsteps/h 1 high user or power user complies with 3 medium users, e.g. call center Named User: Q: How much load creates a named user? A: At first no load It depends on if the user is to be calculated among the concurrent active users Experience: 33 50% of the named users are active to calculate as concurrent users Design guidelines A single virtual machine used to run a full SAP system (i.e., Database, Central Instance and all application instances) requires more resources than a system functioning only as an SAP application server. The virtual machine definition requires the configuration of the virtual processors, virtual memory, virtual storage and virtual networking. Performance benchmarks and characterization define a twoprocessor virtual machine within a Quad-Core Intel Xeon X7350-based ProLiant DL580 G5 server as capable of supporting up to 516 SD users, 2597 SAPs (results as of 3/14/2008 certification ). For sizing purposes, 65% of this number is used for the particular virtual machine. 5

6 Important This guide provides a general sizing overview. This is not to be used as a final sizing recommendation. There are many customer-specific details that can impact the application of the general sizing information presented in this guide. HP recommends proof-of-concept testing in a non-production environment using the actual target application as a matter of best practice for all application deployments. Testing the actual target application in a test/staging environment identical to, but isolated from, the production environment is the most effective way to estimate systems behavior. Sizing methodology The SAP Quick Sizer and HP sizing tools are used to help the customer define the hardware requirements for the desired landscape. Today s tools do not distinguish between a native vs. virtual machine. The process described here illustrates how to use these tools to design a hardware system to support multiple virtual machines running SAP. The example here covers use of VMware ESX Server 3.5 to support several components of the SAP landscape. This particular solution is designed to support 3 application servers, 2 test, 1 training, and 1 development environment. Sizing individual virtual machines An SAP environment requiring two virtual processors is sized based on the number of expected SAPS. Current two-tier standard SAP SD benchmarks illustrate that a ProLiant DL580 G5 server can support 516 SD users, 2597 SAPs (results as of 3/14/2008 certification ). For environments requiring more SAPS, more virtual processors can be allocated. Disk sizing must follow best practice guidelines for SAP systems. The solution definition should still follow the standards of dividing disks and layers of the application. Good system design reserves one processing core for the ESX console. The remaining processing cores are then divided as required by the overall SAP landscape definition. Table 2. General guidelines for virtual environments System # Users Max SAPS vdisk vmem vnic 2P Virtual 2-Tier GB 8GB 1 2P Virtual App server GB 12GB 2 4P Virtual 2-Tier GB 12GB 1 4P Virtual App server GB 16GB 2 6

7 Multi-environment sizing The example below illustrates how a customer scenario might use multiple virtual machines within a single system to support the SAP landscape. System # Users Online SAPS Batch SAPS Virtual Processors Virtual Memory Storage Networking Test # GB 1 Test # GB 1 Dev GB 1 Training GB 1 App # GB 2 App # GB 2 App # GB 2 ESX console GB 2 Totals GB N/A Initially, the total user workload requirements need to be assessed. For example, consider an SAP environment that will accommodate 770 SD users or 3,850 SAPS. HP ProLiant servers are certified to support SAP with this level of workload. The key deciding factor in this example is the number of environments to be virtualized. Overall, the server chosen needs to have a native SAPS rating at least 20% greater than the total SAPS requirement for all virtual environments. For this example, an additional 962 SAPS is required by the server to support the ESX console. To begin understanding the processor requirements of the server, each virtual environment is configured with a minimum of two virtual processors and 8GB RAM. Given the requirement of seven virtual environments, this configuration requires a minimum of 14 processor cores. To support this level of processor requirements in a single server, a Quad-Core Intel Xeon-based system should be defined. For this example, the 4-socket ProLiant DL580 G5 rack mount server is selected. The largest single workload is for either one of the application servers. This 150-user requirement can easily be supported with two virtual processors. Based on benchmarks and lab work, both Intel Xeon and AMD Opteron processor-based servers are acceptable for this configuration. To configure a server for support of the seven virtual environment requirements, take the total processors, memory and storage requirements for the sum of all planned virtual machines. Best practices suggest a single, dedicated network for each virtual machine. Multiport network adapters can be used to reduce the total cards required, although the solution still must follow best practices for network connectivity. For the example presented above, the total SAPS requirement is 7,700 SAPS. Best practices for the ESX console suggest 20% system to support the console OS. Although memory between virtual machines can be made to exceed the total physical memory (i.e. over allocate memory), SAP best practices do not support this type of configuration. To support multiple virtual machines, each running SAP, the total memory of the system is the sum of all SAP systems plus a minimum of 4GB for ESX Server. 7

8 Total storage needs here are in the range of 300 GB. In theory a single local disk could satisfy the pure space requirements of this scenario. To fulfill the storage requirements in terms of I/O performance and the expected growth ratios the connection to an external storage array is recommended. Multiple HP StorageWorks solutions for SAP have the capability to support the storage needs of this scenario. A specific storage solution has to be investigated based on the I/O footprint of an actual SAP customer configuration. The most flexible and dynamic storage solution supporting performance, growth and backup of virtual machines is an HP StorageWorks 4400 Enterprise Virtual Array (EVA4400) as shown in Figure 3. A typical SAP layout on an external storage array looks like: Drive Contents Size LUN C: Microsoft Windows OS 8 10 GB 0 E: SAP EXE 8 10 GB 1 F: MSSQL EXE 4 GB 2 G: MSSQL/SAP Logs 10 GB 3 H: SAP Logs 10 GB 4 I: SAP_Data1 50+ GB 5 K: SAP_Data2 50+ GB 6 L: SAP_Data3 50+ GB 7 To support this type of configuration a solid storage subsystem has to be investigated. Storage The storage requirements for this sample configuration are satisfied using multiple LUNs on an HP StorageWorks EVA4400. Networking Network adapters can be shared by the virtual machines (VMs). The lab tests of the SD benchmark did not require a lot of network bandwidth. For a particular customer solution, the network usage should be analyzed over time to understand any particular requirements. Virtual machine sizing VM process sizing Sizing the virtual machines running the SAP system is based on small SD benchmark tests. Testing of AMD and Intel processors has demonstrated that a single two-processor virtual machine can support 400 or more SD users (1200 SAPS). VM memory sizing Memory is defined by the standard SAP requirements per user. This particular example has specific memory requirements. Each VM is configured at setup time for the required memory. 8

9 VM network Network requirements for each VM are shared using the base network support in the DL580 G5 server. VM storage Storage for each VM is a dedicated LUN on the external disk array. Extra disk space should be considered to allow backups/snapshots of the virtual machine files/luns. Extra hardware The ProLiant DL580 G5 server provides open slots, memory and processors for future growth requirements of this configuration. A good rule is to include extra storage to support backups of virtual machine files. Supplying extra processors and memory allows for growth within the SAP virtual machines. Sample configuration The example configuration looks similar to the following: Figure 3. Reference configuration 9

10 For more information HP Servers, HP Storage, HP ActiveAnswers, For information on HP and SAP, For information on HP and VMware, To help us improve our documents, please provide feedback at Hewlett-Packard Development Company, L.P. The information contained herein is subject to change without notice. The only warranties for HP products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional warranty. HP shall not be liable for technical or editorial errors or omissions contained herein. Microsoft and Windows are U.S. registered trademarks of Microsoft Corporation. AMD and AMD Opteron are trademarks of Advanced Micro Devices, Inc. Intel and Xeon are trademarks of Intel Corporation in the U.S. and other countries. 4AA1-9279ENW, Revision 2, July 2008