SAP database backup and restore solutions for HP StorageWorks Enterprise Virtual Array using HP Data Protector 6.1 software Table of contents Executive summary... 2 Solution overview... 2 Objectives... 2 Configuration... 3 Test environment configuration... 3 Database and storage layout... 4 Using HP Data Protector software... 5 File library device... 6 EML... 6 VTL... 7 ZDB... 8 VDS/VSS... 8 Test objectives... 8 Test cases... 8 Characterizing the impact of a backup on the application... 9 Test results... 10 Time taken to back up the database... 10 Total time taken to back up the database... 11 Time taken to restore the database using the VLS... 12 Impact of backup type on the application... 13 Summary... 13 For more information... 14
Executive summary Backing up SAP databases as fast as possible with the least impact to the production system is increasingly becoming a requirement for SAP customers needing to provide 24 x 7 availability even in mid-sized environments. HP has validated a range of backup solutions based on HP Data Protector 6.1 software in test environments featuring an SAP application in conjunction with a Microsoft SQL Server 2005 database. HP StorageWorks Enterprise Virtual Array (EVA) storage was used in conjunction with different backup devices. The fastest database backup solution with the potential for the least impact on the SAP application was Zero Downtime Backup (ZDB) featuring an HP StorageWorks 6000 Virtual Library System (VLS6000). Target audience: This white paper is intended for SAP system administrators. Testing performed in November 2009 is described. Solution overview The backup and restore solutions described in this white paper were implemented in a simulated business-critical SAP environment using a range of test scenarios. Objectives Objectives for the backup and restore solution included the following: Validate the solution components SAP ERP 2005 SQL Server 2005 Data Protector 6.1 HP StorageWorks Enterprise Virtual Array (EVA) HP StorageWorks Command View for Tape Libraries (CV-TL) Assess the ability of this solution to backup and restore an SAP database using a range of backup devices; test scenarios included local and network backups, zero downtime backup (ZDB), and backups with Microsoft Virtual Disk Service (VDS) and Volume Shadow Copy Service (VSS) The hardware and software components of this solution are described in the following sections. 2
Configuration This section describes the test environment used to validate the backup and restore solution. It is assumed that the SQL Server 2005 database has already been installed and configured on the database server and that this database is connected to an EVA storage array and to a management server. Installation and configuration of these components are not described herein; refer to the appropriate documentation for more information. Test environment configuration Figure 1 provides an overview of the test environment an HP BladeSystem c7000 enclosure housing seven HP ProLiant BL460c server blades, each equipped with two Intel Xeon processors Model X5355 (2.66 GHz) or Model X5160 (3.00 GHz) with PC2-5300 DDR2 memory. Each server included an Emulex LPe1105 FC Dual-Channel 4 Gb PCI-E-to-FC host bus adapter (HBA) to interface with an HP StorageWorks 8100 Enterprise Virtual Array (EVA8100) storage array 1. Figure 1. Solution overview SAP application and database servers were sized according to recommendations made by the HP SAP Competency Center for a medium-sized SAP system. Management and support servers were sized according to recommendations provided in the installation guides for software products hosted on the particular server. Table 1 outlines the server configurations. 1 Model 2C12D 3
Table 1. Server configurations Purpose Processors Memory Platform Model 5355 Model 5160 SAP application server 32 GB x64 Clustered SAP database servers 32 GB x64 Data Protector 6.1 backup server 8 GB x86 Domain controller 8 GB x64 SAP Solution Manager 7.0 8 GB x64 Command View EVA 7.0 (CV EVA), CV-TL 8 GB x86 Database and storage layout The EVA8100 storage array was used to store SAP and SQL Server 2005 executables, SAPDATA files 2, and the database log file. Running XCS 6.110 firmware, this array was populated with 146 GB 15,000 rpm Fibre Channel (FC) disk drives. To enhance availability and performance, two disk groups were used to separate log files (sequential I/O) from SAPDATA files (random I/O). VRAID types and LUN sizes were based on standard ERP 2005 requirements. Tables 2 and 3 outline array configuration and LUN layout. Table 2. EVA8100 storage array configuration Disk group # of disks Capacity Contents SAPDATA 40 2.6 TB SAPDATA1, SAPDATA2, MSDTC, Quorum, SAPEXE, SQL2005EXE, TempDB, CentralInstance, DialogInstance, SolMgr Log files 8 410 GB TransLogs 2 Where SAP database files are stored 4
Table 3. LUN layout Disk drive Disk group LUN size (GB) VRAID level SAP executables SAPDATA 50 5 SQL Server 2005 executables SAPDATA 50 5 SAPDATA database file #1 SAPDATA 300 1 SAPDATA database file #2 SAPDATA 300 1 SAPDATA database file #3 SAPDATA 300 1 SAPDATA database file #4 SAPDATA 300 1 SQL Server 2005 transaction logs Logs 50 1 SQL Server 2005 TempDB SAPDATA 50 1 In general, the EVA storage was configured according to guidelines provided in the HP best practices white paper, HP StorageWorks 4400/6400/8400 Enterprise Virtual Array configuration. Using HP Data Protector software HP Data Protector software helps protect your fast-growing SAP data and provide 24 x 7 business continuity. Data Protector offers comprehensive backup and restore functionality that can be used in environments ranging from a single system to thousands of systems on several sites. A broad range of options allows you to configure a backup infrastructure that can meet your specific needs. Features include: High-performance backup Recovery from disk or tape Lower IT costs and complexity Reliability and scalability to help you grow from a single-server environment to a large, distributed enterprise infrastructure. Data Protector supports a range of devices designed to perform backup and restore operations. These devices, which vary in their functional sophistication and expected usage, include a file library device, an HP StorageWorks Enterprise Modular Library (EML), and virtual tape library (VTL). Descriptions of these devices, along with overviews of ZDB and VDS/VSS backup technologies, are provided below. 5
File library device Designed to accommodate the unattended backup and restore of large amounts of data, the file library device is a sophisticated, easy-to-configure, disk-based device. This device provides multiple slots to which you can back up data; maximum storage capacity is only limited by the amount of data that can be saved in a file system by the particular OS. Using a wizard in the Data Protector graphical user interface (GUI), you can configure a file library device on local storage, a network share, or a storage area network (SAN). For the testing described in this white paper, a file library device was configured on EVA storage for the following backup scenarios: Locally, with the EVA storage connected directly to the SAP database server Over the network with the EVA storage connected to a dedicated backup server featuring five writers (drives) The EVA storage was sized to accommodate the SAP database backup. EML Offering outstanding tape drive and cartridge densities, EML E-Series and ESL Tape Libraries are designed to provide reliability, scalability, and manageability in heterogeneous SAN environments, along with robust data protection and investment protection. Embedded Advanced Encryption Standard (AES) 256-bit encryption is used to provide strong back-up data protection; in addition, the Key Manager feature provides a centralized encryption key management solution. Easy to install and operate, an EML E-Series Tape Library (such as those shown in Figure 2) can be managed as a single library or multiple libraries. Figure 2. Typical EML E-Series Tape Libraries Tape libraries are fully integrated into the HP StorageWorks portfolio through interoperability and compatible-capacity points; furthermore these libraries have been tested extensively with HP StorageWorks Enterprise Backup Solutions (EBS) to validate reliability in demanding environments. 6
Entry configurations start with 71 slots. As you need change, multiple upgrade paths are available; for example: To increase capacity, you can scale out to 505 slots, or To enhance performance, you can deploy 16 LTO-4 Ultrium 1840 or LTO-3 Ultrium 960 FC tape drives and 442 slots. The EML delivers value, agility, and ease of management. For the testing described in this white paper, an EML with five LTO-3 Ultrium tape drives was configured for the following backup scenarios: Locally, connected to an SAP database server Over the network VTL A VTL is a dedicated computing appliance that emulates the drives of a physical tape library while storing backup images to disk. The VTL consists of the following components: Computer hardware Application software, which emulates tape drives and a tape library; you can configure virtual tape drives and virtual tape cartridges, and specify cartridge capacity RAID-based array of disk drives, ensuring that no backup data is lost if a hard drive were to fail You can add virtual tape drives to the VTL simply by changing the software configuration, with no additional hardware costs. The maximum number of supported virtual tape drives varies by vendor. Data Protector can use VTLs such as the HP StorageWorks 6000 Virtual Library System (VLS6000), which is shown in Figure 3. Figure 3. VLS6000 VTL For more information on VTL technology and a comparison with standard tape libraries, refer to the HP white paper, HP Data Protector Software Advanced Backup to Disk Integration with Virtual Tape Libraries. For the testing described in this white paper, a VLS6600 VTL with 24 500 GB SATA disk drives was configured for the following backup scenarios: 7
Locally, connected to an SAP database server Over the network ZDB It has become critical to reduce the time taken to back up and restore data to a minimum so as not to impact the day-to-day running of business-critical applications. ZDB and instant recovery technologies can be used to meet customer requirements for larger, faster solutions for backing up and restoring data. Increasingly, SANs are being used to store vast amounts of mission-critical data in large RAID arrays. Through storage virtualization, an array can be subdivided into virtual disks that can be copied internally within the array; now you can copy data without risk to the original, promoting fast, effective backup solutions and high availability. To minimize disruption to the application, a ZDB utilizes disk array technology such as HP StorageWorks Business Copy EVA software to create a replica of the target data. This replica, which may be an exact duplicate (mirror, snapclone) of the original or a virtual copy (snapshot), can be maintained within the array or backed up to another device. So-called instant recovery capability requires the replica to be stored within the same disk array where the data is to be restored. Because it occurs entirely within the array, the restore can be performed at very high speed. VDS/VSS Microsoft Virtual Disk Service (VDS) and Volume Shadow Copy Service (VSS) are storage management interfaces for Microsoft Windows Server 2003 and 2008, designed to allow thirdparty applications interface with a storage array. VDS implements a communications channel that allows you to send management commands to the array. For example, you can use VDS to create, delete, and unmask volumes, or obtain status and configuration information from the array. VSS can be used to help create snapshot volumes on the array when triggered by a third-party backup application (requestor). For more information, refer to the Microsoft white paper, Storage Management Using Windows Server 2003 and Windows Storage Server 2003 Virtual Disk Service and Volume Shadow Copy Service. Test objectives The testing described in this white paper was designed to validate a software-based backup and restore solution for a 420 GB SAP database on Microsoft SQL Server 2005. The key objectives were to reduce backup time while minimizing the impact on users. Test cases HP tested the following test cases with each of the backup devices described above: Network backup A Data Protector agent reads the data to be backed up from the database server, then sends this data over the network to the backup server, which is responsible for writing the data to the particular backup device. Local backup In this scenario, backup devices are seen locally by the database server. EML and VTL are connected to the database server via FC; no data is transferred over the network. 8
ZDB backup The local replication capabilities of the storage array are used to create a snapshot or snapclone of the database. Without the intervention of the database server, these replicas are then backed up via a backup server 3 to the various backup devices. VDS/VSS backup Alternate storage array capabilities are used to create a replica of the database. Note: With VDS/VSS, you are limited to three LUNs per backup; significantly more LUNs can be backed up with ZDB. Backups to the file library device are performed sequentially; backups to the EML or VTL support some degree of parallelism. Characterizing the impact of a backup on the application To help characterize the impact of the above test cases on an SAP application, HP simulated a typical workload by creating and deleting 100,000 records in the SAP database. With no backup being performed, this workload was completed in 22.4 seconds. Using this response time as a baseline, HP was able to assess the impact of the various test cases on the application. The following section summarizes the test results for each test case and characterizes the impact of each. 3 Running a Data Protector agent 9
Test results This section presents test results in the following areas: Time taken to back up the database (excludes time taken to back up replicas to a backup device) Total time taken to back up the database (includes time taken to back up replicas to a backup device) Time taken to restore the database using the VLS Impact of backup type on the application Time taken to back up the database Figure 4 compares the time taken to back up the SAP database for each of the test cases using the Data Protector File Library, an ESL Tape Library and the Virtual Library System VLS6000. Array-based backups were completed within a few minutes; backups from the database server to backup devices whether performed locally or over the network took significantly longer. The only impact of the array-based backups on the application was that write I/Os to the database were stopped during the short time period required to create the replica. While it is clearly beneficial to minimize the length of time the database server is impacted, note that array-based backups require an additional step so that the replica can be backed up from the array to a backup device. Thus, total backup times for these backups are longer than those shown in Figure 4. Figure 4. Time taken to back up a 420 GB SAP database 10
Total time taken to back up the database Figure 5 shows the total time required to back up the SAP database, including the time taken to back up replicas to backup devices. Figure 5. Total time taken to back up a 420 GB SAP database to the various backup devices The snapclone-based ZDB solution took the most time to complete since Data Protector could not begin writing the replica to the backup device until the EVA had completely finished creating the snapclone. In this scenario, the LUNs housing the SAP database were physically copied by the EVA to the LUNs that were totally independent of the original ones. When a snapshot was used, no data was copied initially; instead, a copy-on-write mechanism was used every time there was a change to the original volume. Thus, while the snapshot was available instantly, it was not independent of the original volume. For more information on using Business Copy EVA replication, refer to the HP white paper, Replicating SQL database using EVA snapshot/snapclone/mirrorclone technology in a SAN environment with RSM and Dbutil. 11
Time taken to restore the database using the VLS Since replicas are independent of the database server, array-based solutions can restore an SAP database almost instantaneously. Figure 6 compares total backup and restore times utilizing the VLS, the fastest of the backup devices. Figure 6. Time taken to backup and restore of a 420 GB database using the VLS The fastest restore solution (known as instant recovery) utilizes the ZDB snapclone. 12
Impact of backup type on the application Figure 7 shows the impact of particular backup types on application performance. This figure compares the additional time taken to complete a simulated SAP workload when particular backup solutions are used (expressed as a percentage). Figure 7. Impact of backups on application performance Array-based backup solutions have significantly less impact on the application. Once the replica of the SAP database has been created, the activity required to secure this data on an additional device takes place on the dedicated backup server, without involving the database server and, thus, without impacting the application. By contract, with non-array-based solutions, the application was impacted until the backup was complete. Summary This white paper outlines a range of scenarios that utilize HP Data Protector to back up a SQL Serverbased database in an SAP landscape to virtual or non-virtual devices. The fastest scenario with the least impact on the SAP application was a ZDB solution using a snapshot created within an HP StorageWorks EVA storage array. 13
For more information HP Data Protector software HP StorageWorks Virtual Library System (VLS) HP Performance Assessment Tools Library and tape tools Backing up to disk with HP Data Protector software Integrating HP Data Protector software with Virtual Tape Libraries Best practices for configuring EVA4400/6400/8400 storage Replicating a SQL Server database using EVA snapshot/snapclone/mirrorclone technology in a SAN environment http://www.hp.com/go/dataprotector http://www.hp.com/go/vls http://www.hp.com/support/pat http://www.hp.com/support/tapetools http://bizsupport2.austin.hp.com/bc/docs/support/s upportmanual/c00668397/c00668397.pdf http://bizsupport2.austin.hp.com/bc/docs/support/s upportmanual/c00868706/c00868706.pdf http://h20195.www2.hp.com/v2/getdocument.asp x?docname=4aa2-0914enw&cc=us&lc=en http://h20195.www2.hp.com/v2/getdocument.asp x?docname=4aa2-5627enw&cc=us&lc=en To help us improve our documents, please provide feedback at http://h20219.www2.hp.com/activeanswers/us/en/solutions/technical_tools_feedback.html. Technology for better business outcomes Copyright 2010 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. Intel and Xeon are trademarks of Intel Corporation in the U.S. and other countries. 4AA0-7547ENW, January 2010