Best Practices for Optimizing SQL Server Database Performance with the LSI WarpDrive Acceleration Card

Best Practices for Optimizing SQL Server Database Performance with the LSI WarpDrive Acceleration Card Version 1.0 April 2011 DB15-000761-00

Revision History Version and Date Version 1.0, April 2011 Initial publication of this document. Description of Change LSI, the LSI & Design logo, WarpDrive, MegaRAID, and MegaRAID Storage Manager are trademarks or registered trademarks of LSI Corporation or its subsidiaries. SQL Server is a registered trademark of Microsoft Corporation. All other brand and product names may be trademarks of their respective companies. LSI Corporation reserves the right to make changes to the product(s) or information disclosed herein at any time without notice. LSI Corporation does not assume any responsibility or liability arising out of the application or use of any product or service described herein, except as expressly agreed to in writing by LSI Corporation; nor does the purchase, lease, or use of a product or service from LSI Corporation convey a license under any patent rights, copyrights, trademark rights, or any other of the intellectual property rights of LSI Corporation or of third parties. LSI products are not intended for use in life-support appliances, devices, or systems. Use of any LSI product in such applications without written consent of the appropriate LSI officer is prohibited. This document contains proprietary information of LSI Corporation. The information contained herein is not to be used by or disclosed to third parties without the express written permission of LSI Corporation. Corporate Headquarters Email Website Milpitas, CA globalsupport@lsi.com www.lsi.com 800-372-2447 Document Number: DB15-000761-00 Copyright 2011 LSI Corporation All Rights Reserved

Table of Contents Best Practices for Optimizing SQL Server Performance with the LSI WarpDrive Acceleration Card.................................... 4 1.1 Advantages of Using Solid-State Storage with a Database............................................................................4 1.2 Configuring an SQL Server Database to Use LSI WarpDrive Acceleration Cards........................................................4 1.3 Tuning the Server Operating System and the SQL Server Database for Better I/O Performance.........................................6 1.3.1 Monitoring and Tuning the Operating System................................................................................ 6 1.3.2 Monitoring the WarpDrive Acceleration Card................................................................................ 11 1.3.3 Creating Storage Redundancy with Software RAID Using Multiple WarpDrive Cards........................................... 12 1.3.4 Monitoring the SQL Server Database......................................................................................... 13 1.3.5 Increasing I/O Efficiency at the Database File Level........................................................................... 14 1.4 System Test Results................................................................................................................14 1.4.1 Test System Description..................................................................................................... 14 1.4.2 Test Database Settings...................................................................................................... 15 1.4.3 HDD Drive Layout Configuration............................................................................................. 15 1.4.4 SSD Drive Layout Configuration............................................................................................. 15 1.4.5 HDD Performance Data...................................................................................................... 15 1.4.6 SSD Performance Data...................................................................................................... 16 1.4.7 Performance Data Comparison.............................................................................................. 16 1.4.8 Test Conclusion Summary................................................................................................... 19-3 -

Best Practices for Optimizing SQL Server Performance with the LSI WarpDrive Acceleration Card This document explains how to achieve significant performance gains in your SQL Server database applications by using the LSI WarpDrive acceleration card. Offering high performance with low latency and a low CPU burden, the solid-state storage PCIe small form factor WarpDrive card maximizes transactional I/O performance for applications such as online transaction processing (OLTP). Delivering the I/O performance of hundreds of traditional disk drives, the WarpDrive card enables an SQL Server database to meet your service-level agreements for response times and throughput. 1.1 Advantages of Using Solid-State Storage with a Database OLTP is a typical application workload that is used with SQL Server database applications. OLTP has demanding requirements for short response times and high throughput, which makes it difficult for database administrators (DBAs) to maintain these systems as the number of users grows and the amount of data increases. The SQL queries, the network, the server, and storage can each cause performance bottlenecks during the application life cycle. Correcting a bottleneck in one area may cause another bottleneck to appear in another area. Solid-state storage provides a new tool for DBAs to solve their storage bottlenecks. For example, the typical response time for a small data read from a hard disk drive is, on average, 1 millisecond to 10 milliseconds, dependent on the workload. Flash-based devices like the LSI WarpDrive acceleration card can complete the same read, on average, in 50 microseconds to 300 microseconds, an improvement of several orders-of-magnitude in response time. Based on flash memory technology, solid-state storage provides performance levels that fall between hard disk drives and DDR3 server memory. Initial enterprise-level flash products have been solid-state drives (SSDs) which are intended to replace hard disk drives. A recent innovation has been mounting SSDs on a PCIe card, which alleviates throughput constraints caused by the storage interface. The LSI WarpDrive solid-state storage acceleration card supports up to 1.2 Gb/s and over 200K input/output operations per second. You can achieve higher levels of performance by using multiple WarpDrive cards. 1.2 Configuring an SQL Server Database to Use LSI WarpDrive Acceleration Cards This document describes best practices for using the LSI WarpDrive acceleration card in an SQL Server database environment and lists the measured performance improvement over using hard drives. If the database is smaller than the capacity of the installed solid-state storage, you can move the entire database to the WarpDrive card. For large databases that exceed the card s capacity, you can achieve significant performance improvement by moving specific database data files to the card while leaving the log file on hard disk drives. Data files have a random pattern, but log files are sequential. Because WarpDrive acceleration cards have no spinning disk latency, they excel with random I/O transactions. Sequential writes or reads are not appreciably faster than hard disk drives. You should move randomly accessed data like an index file or a data file to the WarpDrive acceleration card. Leave the log files on the hard disk drives, because they are sequentially written. You can use pairs of WarpDrive acceleration cards with data mirrored across them to protect the data in the event of a board failure. For data mirroring, you can use programs such as the Windows Server operating system disk mirror product offering. In LSI tests, we created a Windows Server 2008 R2 disk mirror over two WarpDrive cards. We used the mirror function when creating the volumes to provide redundancy. This configuration is often referred to as software RAID level 1. - 4 -

This section provides information about the LSI WarpDrive 300-GB SLP-300 PCIe solid-state storage acceleration card. The following figure shows the WarpDrive card. Figure 1 WarpDrive Acceleration Card The WarpDrive acceleration card offers high performance with low latency and a low CPU burden. The card maximizes transactional I/O performance for SQL Server databases and for other applications that require high-performance computing. The WarpDrive acceleration card performs consistently across reads and writes regardless of workload, using industry-standard and widely deployed LSI SAS software for easier system integration and management and a faster time to market. The WarpDrive acceleration card has the following features: PCIe small form factor 300 GB of storage (uncompressed) PCIe 2.0 host interface Error-correcting code (ECC) protection up to 24 bits per 512 bytes LSISAS2008 controller Powered entirely by the PCIe slot; no external power requirements; consumes less than 25 W Small form factor PCIe board-level solid-state storage Low latency, minimal CPU burden and host memory footprint Performance optimized, best-in-class for reads and writes Simple integration using SAS infrastructure Enterprise reliability Support for plug-and-play Bootable Supports the Windows operating system and the Linux operating system Up to 240K 4-KB read input-output operations per second (IOP/s) Up to 200K 4-KB write IOP/s Average latency of less than 50 μs Low host burden; no static CPU and memory overhead Software optimized for SSD performance - 5 -

1.3 Tuning the Server Operating System and the SQL Server Database for Better I/O Performance You can achieve significant database I/O improvement by tuning the Windows operating system and the SQL Server database. This section lists some monitoring and tuning tips that you can implement before introducing the LSI WarpDrive acceleration cards to the configuration. The WarpDrive acceleration card is based on SSD technology that uses garbage collection and wear-leveling technology to help evenly distribute page and block write and erase operations across the drive. These tasks require free blocks on the drive. LSI overprovisions the WarpDrive card 30 percent by default. In addition, users can extend the overprovisioning amount when configuring the volume in Windows Disk Management. 1.3.1 Monitoring and Tuning the Operating System The WarpDrive acceleration card is based on SSD technology that uses garbage collection and wear-leveling technology to help evenly distribute page/block write and erase operations across the drive. These tasks require free blocks on the drive. LSI overprovisions the WarpDrive card 30 percent by default. In addition, you can extend the overprovisioning amount when configuring the volume in Windows Disk Management. 1.3.1.1 Best Practice 1 Format the LSI WarpDrive card using the formatting tools that LSI provides. When: Before you create volumes with Windows Disk Management. How: Use either the MegaRAID Storage Manager tool or the WarpDrive PCIe Solid-State Storage Card Management Utility (ddcli.exe utility). Refer to the LSI website for specific documentation and instructions on formatting WarpDrive cards with the MegaRAID Storage Manager tool or the WarpDrive PCIe Solid-State Storage Card Management Utility (ddcli.exe utility). Benefits: If you format the WarpDrive card with the tools that LSI supplies, you ensure that all data has been erased from the drive. NOTE Formatting erases all data on the WarpDrive card. - 6 -

1.3.1.2 Best Practice 2 Overprovision the LSI WarpDrive volume from 20 percent to 50 percent as needed, depending on the projected write workload. When: Creating a Windows volume with the WarpDrive acceleration card. How: In the Windows Disk Management application, select the amount of space in MB to provision relative to the maximum available space in MB, as shown in the following screen shot. Figure 2 Creating a Windows Volume Benefits: Overprovisioning allows necessary free blocks to store update blocks during the wear-leveling and garbage collection process, to increase the life of the SSD drive. - 7 -

1.3.1.3 Best Practice 3 Disable drive indexing on the LSI WarpDrive card volume. When: After you create the WarpDrive card volume. How: Select the WarpDrive card volume properties in Windows and disable the indexing feature, as shown in the following screen shot. Figure 3 Disabling Drive Indexing Benefits: Minimizing background write activity to the WarpDrive card volume increases performance and lifespan. - 8 -

1.3.1.4 Best Practice 4 Manually configure the Windows Page File to use a custom size instead of the default system managed size. When: Before testing workloads. How: In the Windows Virtual Memory property, set a custom page file initial size and maximum size to create a static size, as shown in the following screen shot. Use the recommended page file size values for the initial and maximum values, if possible. Figure 4 Configuring the Windows Page File Benefits: A custom page file size uses fewer operating system resources and reduces disk contention to allocate page file space as needed, thereby improving system performance. - 9 -

1.3.1.5 Best Practice 5 Disable the Windows Power Saving features on the host, and disable any server BIOS power saving features. When: Before testing workloads. How: In the Windows Control Panel, select the high performance-plan, as shown in the following screen shot. Refer to the vendor manufacturer documentation for information about server BIOS power saving features. Figure 5 Disabling Windows Power Saving Benefits: Selecting the high-performance power plan ensures that components are not constrained, such as processor throttling. To monitor system resources on a Windows system, run the Windows Performance Monitor Perfmon application counters. If you use these utilities during testing, you can see any improvements made after each change to the system. Perfmon contains Windows operating system counters as well as counters specific to the SQL Server database. - 10 -

1.3.2 Monitoring the WarpDrive Acceleration Card This section explains some tools that are available for monitoring the LSI WarpDrive acceleration card. WarpDrive PCIe Solid-State Storage Card Management Utility You can use the ddcli command line utility to assess the health of the selected WarpDrive card. The ddcli utility provides the following features: Lists WarpDrive information Updates the flash package Displays WarpDrive health Locates WarpDrive cards Formats WarpDrive cards MegaRAID Storage Manager Tool Starting with version 9.00.0100, the MegaRAID Storage Manager tool provides a graphical user interface for monitoring WarpDrive cards in dashboard, physical, and logical views. The MegaRAID Storage Manager tool enables you to update the controller firmware package and formatting. The dashboard view lists the following information. Figure 6 MegaRAID Storage Manager Dashboard Refer to the LSI website for more information about installing, configuring, and using these WarpDrive monitoring tools. - 11 -

1.3.3 Creating Storage Redundancy with Software RAID Using Multiple WarpDrive Cards The LSI WarpDrive acceleration card does not provide data redundancy using a single card. To provide redundancy for production data when using the WarpDrive card, LSI tests have verified that you can mirror data over two installed WarpDrive cards to eliminate a single point of failure. We performed the testing using two WarpDrive cards along with Windows software mirroring to create the storage for the SQL Server database. We used the following process to configure a software mirror volume over two WarpDrive cards: 1. In the Windows Disk Management application, create a mirrored volume, as shown in the following screen shot: Figure 7 Configuring a Mirrored Volume 2. Select the desired size for the mirrored volume, as shown in the following screen shot: Figure 8 Selecting the Size for the Mirrored Volume - 12 -

3. Format the mirrored volume and select a 64K allocation unit size, as shown in the following screen shot. The SQL Server database uses 64K extents for storage space. NOTE This process converts the volumes from a basic disk to a dynamic disk. Figure 9 Formatting the Mirrored Volume CAUTION We successfully completed all of these system and storage modifications in our lab to perform our benchmark tests. Before implementing any of these modifications in your environment, make sure to test them completely to determine whether to use them in your environment. 1.3.4 Monitoring the SQL Server Database The SQL Server database provides dynamic management views (DMVs) to monitor the engine internals. To help reduce storage subsystem-related wait types, you can distribute the sequential and random patterns of the different types of workloads to dedicated storage. The WarpDrive acceleration cards in particular can accommodate many write requests at once with very low latency. This type of activity can be observed during the SQL Server database checkpoint process. The checkpoint process occurs when dirty pages (pages in the database buffer pool that are modified but not written to disk) are flushed and written to disk, first to the log file and then to the data files. One of the reasons checkpoints occur is based on the default recovery interval to minimize the time it takes for database recovery. In high transaction OLTP databases, checkpoints can occur frequently. Our tests show how the WarpDrive card minimizes response times during this operation. Here are brief descriptions of some very useful SQL Server features for monitoring the database. The DMV sys.dm_os_waiting_tasks lists wait type information about the tasks that are delaying the SQL Server database from servicing a request. The DMV sys.dm_io_virtual_file_stats lists I/O statistics information for database files. - 13 -

1.3.5 Increasing I/O Efficiency at the Database File Level This section contains some tips on improving I/O efficiency at the database level. Best Practice: Place system database files on dedicated volumes that are not shared with the Windows operating system or with the Windows operating system page file. When: Database system file locations can be set during the database engine configuration (Data Directories) installation. How: During the database engine configuration (Data Directories) installation process, specify the system database (msdb, master, model, tempdb) directory targets. Benefits: Placing the system database files on dedicated volumes that are not shared with the Windows operating system prevents disk resource I/O competition between the operating system and the SQL Server database engine. NOTE During our tests of the user database and the system database, files were located on the same Windows mirrored volume. The files were positioned like this only for purposes of testing various workloads. Separating the database log and the data files to their own dedicated volumes/physical disks is a best practice in a production environment to match workload types such as random and sequential. Always evaluate your configuration and workload in a test environment before deploying it in a production environment. 1.4 System Test Results This section describes the system we used to test SQL Server database performance improvements using LSI WarpDrive acceleration cards. It also describes the results of the multistage test procedures to improve database performance. 1.4.1 Test System Description In LSI testing, we ran tests similar to TPC-E and measured significant gains with WarpDrive cards over using HDDs in a direct attached RAID configuration. We used the following test system configuration: ProLiant DL370 G6 server Dual Xeon processor X5570 48 GB - 1333 DDR3 MegaRAID SAS9280-8e board LSI SAS 2x36 expander Twenty-four HP DG0146FAMWL disk drives: 146-GB 2.5-in. small form factor 6G SAS 10K RPM drives Windows Server 2008 R2 Enterprise operating system SQL Server 2008 R2 Enterprise Edition platform The benchmark for these tests was performed using the Microsoft TPC-E toolkit. The TPC-E standard simulates an OLTP workload for a brokerage firm. The specification includes a mix of transaction types related to trades, account inquires, and market research. Tests consisted of a 5000-customer-sized database with 17 users. The maximum transactions (all types) per user rate was 150 per second (pacing) with low latency for transactions. This user load resulted in a heavily accessed system for disk I/O. NOTE TPC-E transactions are defined according to the TPC-E standard specification compared to the SQL Server transaction definition, which is based on a single logical unit of work. The SQL Server transaction definition is based on the atomicity, consistency, isolation, and durability (ACID) properties which the SQL Server database implements. - 14 -

1.4.2 Test Database Settings We used these database settings for all of the tests: SQL Server collation was set to use Latin1_General_Binary. SQL Server memory settings were 4000 MB minimum and 8000 MB maximum. Test database log file growth was set to unrestricted. 1.4.3 HDD Drive Layout Configuration The following table lists the SQL Server HDD configuration used in the test. SQL Server Files Number of LUNs Number of Drives RAID Level Usable Capacity Data 1 8 10 374GB short stroked Log 1 8 10 375GB short stroked tempdb 1 6 1 300GB short stroked 1.4.4 SSD Drive Layout Configuration The following table lists the SQL Server SSD configuration used in the test. SQL Server Files Number of LUNs Number of Drives RAID Level Usable Capacity Data, Log, tempdb 1 2 1 279GB 1.4.5 HDD Performance Data We used Windows Perfmon counters during the tests to capture workload results at the logical volume layer of the operating system. Avg. I/O Read Avg. I/O Write Avg. Throughput Read Avg. Throughput Write Avg. Latency Read Avg. Latency Write 1502 IOP/s 307 IOP/s 12.3 MB/s 2.9 MB/s 23 ms 25 ms We used the following SQL Server Perfmon counter to capture workload results for checkpoint operations during the test period. Number of pages flushed during an operation that requires all dirty pages to be flushed from the buffer. SQLServer:Buffer Manager\Checkpoint pages\sec The following table shows the SQL Server Buffer Manager Checkpoint results: Avg. Pages Max. Pages 214/s 5894/s - 15 -

1.4.6 SSD Performance Data We used the Windows host Perfmon counters during the tests to capture workload results at the logical volume layer of the operating system. Avg. IOP/s Read Avg. IOP/s Write Avg. Throughput Read Avg. Throughput Write Avg. Latency Read Avg. Latency Write 4,525 IOP/s 742 IOP/s 37 MB/s 7.7 MB/s 192 μs 353 μs We used the following SQL Server Perfmon counter to capture workload results for checkpoint operations during the test period. Number of pages flushed during an operation that requires all dirty pages to be flushed from the buffer. SQLServer:Buffer Manager\Checkpoint pages\sec The following table shows the SQL Server Buffer Manager Checkpoint results: Avg. Pages Max. Pages 441/s 47923/s 1.4.7 Performance Data Comparison 1.4.7.1 Transaction Data We achieved significant performance gains when using the LSI WarpDrive acceleration card in a test similar to TPC-E. The test we used is a nonsynthetic test simulating real-world transactions and response times from the application layer. We observed nearly 3X performance gains for transactions per second with the WarpDrive cards when compared to traditional hard drives. The following figure shows the performance improvements. Figure 10 Transaction Performance Improvement - 16 -

1.4.7.2 Response Time Data Reducing application response times improves the user experience. Our test workload also measured response time metrics from the application layer with a workload consisting of read-only and read-write transaction types. We achieved lower response times for the following transaction types when utilizing the LSI WarpDrive acceleration card during our tests, as shown in the following figure. Figure 11 Response Time Comparison Here is a description of the transaction types shown in the figure. T1: Simulates reviewing an account statement that covers a specific period of time. This SELECT query requires accessing multiple tables that require many reads to storage. The faster response time of the WarpDrive cards compared to HDDs is magnified by the large number of input transactions. T2: Simulates retrieving an item on an account statement and updating the entry. This SELECT query is followed by an UPDATE query. T3: Simulates reviewing an account statement that covers a specific period of time and updating the entry. This SELECT query requires accessing multiple tables that require many reads to storage followed by an UPDATE query. The faster response time of the WarpDrive cards compared to HDDs is magnified by the large number of input transactions. - 17 -

1.4.7.3 Performance Data Comparison Using Database Compression The SQL Server database can compress data both at the row level and at the page level. We used page compression in our tests, which improves individual row data space utilization per page. However, there is a trade-off for space savings and increased CPU utilization overhead. The data in the following figure shows the performance and cost associated with using SQL Server page database compression for all indexes and tables in the testing database in an LSI WarpDrive environment while using the same workload that is similar to TPC-E. We observed the following performance gains during our tests. Using the WarpDrive acceleration card in a compressed database environment complements this SQL Server feature, increasing transaction throughput capabilities. Figure 12 Transaction Data with Database Compression - 18 -

1.4.7.4 Overhead Cost Data As stated in the previous section, there is a performance penalty associated with using database compression. The following figure shows CPU utilization for compression versus no compression. For reference, we used CPU Perfmon counters to measure the effect on CPU during the test workloads. Figure 13 CPU Utilization with Compression 1.4.8 Test Conclusion Summary The LSI WarpDrive acceleration card brings performance capabilities that are not possible in a traditional HDD environment. For high-transaction OLTP environments requiring high throughput, high I/O processing rates, and low latency, the WarpDrive card complements any environment. Database administrators now have an additional tool that allows their organization to exceed its SQL Server transaction demands. - 19 -