EMC Backup and Recovery for Microsoft SQL Server 2008 Enabled by EMC Celerra Unified Storage Applied Technology Abstract This white paper describes various backup and recovery solutions available for SQL Server. This paper lists the features of each backup solution and compares various characteristics, such as throughput, encryption, and compression. May 2010
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Table of Contents Executive summary... 4 Introduction... 5 Backup and recovery solutions... 7 Importance of storage in the backup and restore environment...11 Considerations to select a backup solution...12 Conclusion...14 References...15 Applied Technology 3
Executive summary Business case Microsoft SQL Server has rapidly become the database of choice for a large number of prepackaged and custom-built business applications due to its product feature set, ease of use, and competitive pricing. Because SQL databases are highly critical, they need to be backed up. Data can get corrupted or accidentally lost and this in turn affects the applications. If this occurs, a backup of the data will be required to restore the applications to proper working order. Key results In database environments, data can be backed up using different methods based on the requirements. A comparison of the various backup and recovery options from various vendors was done based on attributes such as throughput and storage utilization. Microsoft Data Protection Manager (DPM) and SQL Native provide high backup and restore throughput. Quest LiteSpeed greatly reduces the backend space utilization. However, the backup and restore throughput is low. EMC NetWorker provides greater security and compression. As a result, the storage utilization is reduced to a great extent. The throughput is also comparable with the other backup solutions. Applied Technology 4
Introduction Purpose There are several backup solutions available from different vendors. This white paper presents these solutions and examines them based on the throughput, cost, and storage utilization. Scope This white paper is not intended to be a comprehensive guide about how to select a suitable backup and recovery solution for SQL databases, but it can be used as a suitable reference for readers who want to select a suitable backup solution for their environment. Audience This document is intended for internal EMC personnel, partners, and customers who need to implement a backup and recovery solution for their environment. Terminology Term Definition Common Internet File System (CIFS) Data Mover Fibre Channel (FC) Internet SCSI (iscsi) logical unit number (LUN) Microsoft SQL Server 2008 RAID 1 RAID 1/0 (mirrored individual access array without parity) RAID 5 A protocol to request file and print services over TCP/IP networks. A Celerra Network Server cabinet component running the data access in real time (DART) operating system that retrieves files from a storage device and makes the files available to a network client. A protocol for sending SCSI packets over FC networks. A protocol for sending SCSI packets over TCP/IP networks. The identifying numbers of a SCSI or iscsi object that processes SCSI commands. The LUN is the last part of the SCSI address for a SCSI object. LUN is an ID for the logical unit, but the term is sometimes used to refer to the logical unit itself. A database application from Microsoft Corporation that is the target application for this test plan. RAID 1 provides data integrity by mirroring (copying) data onto another disk. This RAID type provides the greatest assurance of data integrity at the cost of disk space. RAID 1/0 provides the same individual access features as the RAID 5 type, but with the highest data integrity. This RAID type is ideal for applications where data integrity is more important than the cost of disk space. Data is striped across disks in large stripes. Parity information is Applied Technology 5
stored so data can be reconstructed if needed. One disk can fail without any data loss. Performance is good for reads but slower for writes. RAID group recovery point objective (RPO) recovery time objective (RTO) redundant array of inexpensive disks (RAID) The CLARiiON storage system term for a Celerra disk group. In a CLARiiON storage system, a RAID group is a set of physical disks with a RAID type on which one or more LUNs are bound. Each RAID group supports only the RAID type of the first LUN bound on it, and any other LUNs bound on it have that same RAID type. LUNs are distributed equally across all the disks in the RAID group. The point in time (prior to the outage) to which systems and data must be restored. The maximum tolerable length of time that a computer, system, network, or application can be down after a failure or disaster occurs. A method used to store information where the data is stored on multiple disk drives to increase performance and storage capacities and to provide redundancy and fault tolerance. Applied Technology 6
Backup and recovery solutions Introduction The backup utility helps to recover data after a loss due to hardware failure, back-end storage failure, or data corruption. For example, if the original data is lost or corrupted due to any of these threats, the data can be instantly restored from the backed-up copy. Determining the appropriate method is based on business requirements or service level agreements. When selecting the backup solution, factors such as the database environment, network speed, backup media, disk performance, cost, restore throughput, and security should be considered. Data should be restored as soon as possible, keeping in mind factors like recovery point objective (RPO) and recovery time objective (RTO). Types of backup Backups can be of two types: Traditional backup Virtual Shadow Copy Service (VSS) snapshot backup The traditional backup methods include hot and cold backups. A hot backup, also called a dynamic backup, is performed while the data is still being accessed by the application or end users. Most databases have a set of backup APIs or procedures that put the database into a "backup state." This is the state where all current transactions to the main database are completed and committed, and future transactions are logged in to the transaction log files. The main database is backed up along with its transaction logs. This type of backup leaves the application running. However, during the hot backup, the performance of the database is affected. A cold backup, also called an offline backup, is performed when the database is offline. This ensures the completion of all transactions. However, it requires an application downtime, and therefore, is not feasible for all application environments. A snapshot backup is created instantaneously and provides a point-in-time copy of the data. With snapshot technology, a point-in-time view of the SQL database is "snapped" and then backed up, leaving the actual SQL database open and available for users. The SQL agent only supports full snapshot backups. Filegroup snapshots, log snapshots, and differential snapshots are not supported. Microsoft recommends snapshot backups instead of traditional backups. Irrespective of the backup type used, data can be backed up in one of the following methods: Full backup: Backs up the complete set of folders and files. The advantage of full backup is that it provides a complete copy of all the data and is easy to locate files to restore. The procedure is easiest with this backup method because only one backup file is used to restore the data. The disadvantage Applied Technology 7
of full backup is that it takes a long time to complete and uses more space. Incremental backup: Backs up those files that have changed since the last full, incremental, or differential backup. The advantage of this backup is that it takes less time because it backs up only a fraction of the data. Also, the backup storage utilization is low. However, during a restore operation, each of the incremental backup files must be processed and restored in the correct order, so the restore procedure is complicated. Differential backup: Backs up only the changed files since the last full backup. This type of backup should be performed at regular intervals. The advantage of this type of backup is lower storage utilization as compared to a full backup. Also, the restore procedure is less complicated than the incremental restore procedure. However, the disadvantage is that it takes longer to perform a differential backup than an incremental backup. Additionally, subsequent backups take longer to perform as more and more files are changed. Transaction log backups: Unlike database and differential backups, transaction log backups match the state of the database at the time that the backup is started. These backups use less space and take less time than database backups and should be taken more frequently than other backups. Different backup and restore solutions There are many types of backup and recovery solutions available for SQL Server and often it is not easy to choose between them. The various backup solutions include the following: Microsoft SQL Native Backup Quest LiteSpeed EMC NetWorker EMC NetWorker Module for SQL Server (NMSQL) Microsoft System Center Data Protection Manager (DPM) Microsoft SQL Native Backup Microsoft SQL Server 2008 has its own backup and restore facilities, and it provides a large variety of features to enable an organization to deploy database-related applications effectively and with ease. The SQL Server Native Backup system works in conjunction with the transaction log. The enhanced features add value to the management, scalability, performance, high availability, security, development, and business intelligence aspects of the database server. Microsoft SQL Server 2008 comes with a management tool, SQL Server Management Studio, which eliminates the need for a separate system to manage the SQL server. SQL Server Management Studio provides scheduling and management tools along with a query executor to run T-SQL queries. Applied Technology 8
SQL Native Backup creates smaller backup files compared to the size of the database files. Thus, backing up SQL databases using SQL Native Backup has the added advantages of saving disk space and reducing network traffic over other backup methods that do not support compression. Quest LiteSpeed LiteSpeed from Quest Software is a cross-platform, client/server application that provides the ability to remotely manage all LiteSpeed clients and servers from a graphical user interface. The LiteSpeed server backs up SQL Server databases regularly by using scheduled backups. This is preferred over manual backups because they occur automatically and the data can be recovered easily. The impact of LiteSpeed backups on SQL Server is minimal. Moreover, it has a high-performance compression technology. It also reduces storage costs and backup and recovery windows. LiteSpeed is a very flexible tool for maintenance. LiteSpeed allows for the restoration of individual database objects, offers migration to another SQL Server, and has enterprise-wide deployment and upgrade features through its remote installation capability. Quest LiteSpeed offers 10 levels of compression, so based on the environment it can be configured for optimum performance. LiteSpeed provides backup and restore for SQL database and transaction logs. It provides an enterprise view of the backup and recovery environment through GUI and provides for internal scripting backup and recovery commands through T-SQL or a fully functional command line interface. EMC NetWorker EMC NetWorker provides the ability to protect an enterprise against data loss. As the enterprise grows, so does the complexity and importance of protecting data. The NetWorker software provides the power and flexibility to meet these challenges. The NetWorker software is a cross-platform, client/server application that provides the ability to remotely manage all NetWorker clients and servers from a web-enabled, graphical interface. The NetWorker server backs up client data regularly by using scheduled backups. Scheduled backups are preferred over manual backups because they occur automatically and data can be recovered more easily. The NetWorker Module for SQL Server (NMSQL) is a NetWorker add-on module that provides application-consistent backup and restore for SQL database and transaction logs. The NetWorker software provides backup and restore capabilities for file system data only. A file system backup, however, does not save SQL Server data in a recoverable form. EMC NetWorker Module for SQL Server NMSQL is a NetWorker add-on module that enables the NetWorker software to back up and restore Microsoft SQL Server data. NetWorker software provides backup and restore capabilities for the file system data only. However, a file system backup does not save SQL Server data in a recoverable form. Applied Technology 9
NMSQL software supports NetWorker PowerSnap Modules, which are interfaces between a snapshot-capable storage subsystem and the NetWorker and NMSQL software. By using the PowerSnap Module appropriate for the SQL Server storage subsystem, point-in-time (PIT) copies (snapshots) of Microsoft SQL Server 2000 and 2005 data can be created and managed. The NMSQL supports snapshot operations in environments where SQL components are located on hardware that comprises of multiple storage subsystems, provided that each storage subsystem is snapshot-capable. NMSQL provides a fast, online backup and restore for SQL Server databases, ensuring availability of mission-critical application data. This NetWorker Module supports the NetWorker PowerSnap Module software, which provides enhanced data protection through snapshot technology. It provides the Microsoft Cluster Server (MSCS) support to perform backup and recovery operations in a clustered virtual server configuration. Microsoft System Center Data Protection Manager DPM is part of the System Center family of management products from Microsoft. It delivers unified data protection for Windows servers such as SQL Server, Exchange, SharePoint, Virtualization and file servers. Microsoft System Center DPM provides an efficient disk-based data protection and recovery solution. DPM makes use of advanced features such as replication, policy-driven protection, and Windows Server VSS. Instead of replicating an entire file when a change occurs, DPM replicates only the bytes that actually change within each file. Microsoft is able to routinely capture shadow-copy snapshots and perform long-term tape backups, instead of trying to maintain backups from each remote site. This significantly lowers the time, bandwidth, and overall cost required to remotely protect a site. Applied Technology 10
Importance of storage in the backup and restore environment Considerations Backup to disk refers to writing the backup data to a file system on the disk. The advantage of backup to disk is to enable significantly faster backups, and more importantly, to provide faster restores. There are many factors that affect the performance of backup to disk. The main factors are: Type of disk used for backup RAID types used for the backup destination Striping and hot spares Data alignment on the LUNs The type of disk used as the backup destination is critical because it determines the rate at which the backup operation occurs. Therefore, selecting the right backup media is important. The considerations for selecting the backup drives are performance, speed, and cost. The different types of disks available are FC, SATA, SAS, and the new-generation Enterprise Flash Drives (EFDs). The FC drives are faster compared to the SATA or ATA drives. They dramatically increase performance through improvements in disk operations such as rotational latency and seek rates, which are the factors that most directly affect the access times. The selection of the RAID type is another factor that decides the efficiency of the backup. The selection of RAID is application dependent. The cost of a system is directly proportional to the number of disks it uses in the disk array. The performance and cost of RAID level 1 systems are equivalent to the performance and cost of RAID level 5 systems when the parity group size is equal to 2. The performance and cost of RAID level 3 systems are always less than or equal to the performance and cost of RAID level 5 systems. Applied Technology 11
Considerations to select a backup solution Introduction When selecting a backup solution, several attributes such as the performance, security, and cost are to be considered. Some of the attributes that decide the efficiency of a backup solution are: Throughput and performance Storage utilization Security Management Cost An efficient backup and recovery solution must use minimum back-end storage space with minimum cost, must be easy to manage, and must provide maximum functionality and performance. After the first SQL Server backup is completed, subsequent backups should use minimum storage which in turn, reduces the total cost of ownership (TCO). The following table compares the various backup solutions on various attributes. Attributes QLS Microsoft DPM NetWorker SQL Native Backup throughput 6.88 40.7 9.24 30.41 Restore throughput 4.5 48.5 5.0 48.5 Backup size 125 GB 200 130 GB 112 Cost Licensed Licensed Licensed Free Encryption Yes Yes Yes Yes Compression Yes No Yes Yes Ease of setup Easy Easy Easy Easy Management GUI Console Console GUI Traditional Traditional Traditional Traditional Backup types backup, backup, backup, backup, Snapshot Snapshot Snapshot Snapshot backup backup backup backup Compression and encryption Quest LiteSpeed Engine for SQL Server is a driver-based technology that allows database backup administrators to seamlessly take advantage of LiteSpeed s compression and encryption technology without modifying the existing SQL scripts. Also, the more compressible the data is, greater is the backup throughput. The backups are secured with an integrated encryption. Quest LiteSpeed offers nine embedded encryption levels that are applied to data concurrent with the backup process and the encryption process has minimal effect on the backup process. Applied Technology 12
The Microsoft Data Protection Manager uses VSS point-in-time snapshots that reduce the disk volume required, while Express full backup images increase the number of available restore points that can be captured. The Microsoft Data Protection Manager supports data encryption by using the protection group. The SQL Server 2008 Enterprise and later editions support backup compression. By default, a backup is compressed based on the value of the backup-compression default server configuration option. EMC NetWorker applies compression to all marked databases before writing the backup data to the back-end storage. Compressing data for backup generates less network traffic and uses less backup media space but consumes additional CPU resources. Compared to the other solutions, EMC NetWorker offers improved authentication, auditing, and security management. It supports Advanced Encryption Standard (AES) data encryption during backup and restore. This ensures that data is encrypted as it traverses a network and when it is stored on the backup media. NetWorker offers enhanced security by adding a new 256-bit encryption directive that can be applied to backups at the client before sending data. NetWorker has long led the way in snapshot management for instant data protection and rapid recovery as well as backup-to-disk to further accelerate recovery of the data. Price and ease of implementation and management The configuration of Quest LiteSpeed is easy and includes setup wizards and management screens. The backups triggered using Quest LiteSpeed can be managed through wizard tools. The user can specify the kind of backup, full or differential, and can schedule the backups. The Microsoft DPM installation involves installing the DPM application and the DPM prerequisite software. DPM enables rapid and reliable recovery through advanced technology for enterprises of all sizes. The Patented Block Level Filter technology shortens full backup windows by only moving changed data. DPM Administrator Console is the central management tool for DPM, with a consolidated interface that gives you immediate access to the Monitoring, Protection, Recovery, Reporting, and Management task areas. SQL Native Backup is built in to SQL Server 2008 Enterprise. The management of the backups initiated from here can be done using the GUI. This helps in scheduling the backups, whether full, differential or incremental. The backup and recovery process initiated from NetWorker is managed by the NetWorker Management Console (NMC) client. It has advanced features that are easy and has a built-in reporting with a drive utilization report giving information you need to make changes to optimize performance. Applied Technology 13
Conclusion Summary Many of today's backup solutions offer a wide array of backup options. Selecting a suitable solution depends on the customer requirement. The main aims of selecting a solution are significant throughput and minimal storage utilization. This white paper discussed and compared the different backup and recovery solutions available for SQL Server based on various backup attributes. When selecting a backup solution, these attributes are to be considered. The Microsoft DPM solution and the built-in SQL Native provide high backup and restore throughput compared to the other solutions. Quest LiteSpeed greatly reduces the back-end space utilization compared to the other solutions. However, the backup and restore throughput is low. EMC NetWorker provides greater security and compression compared to the other solutions. As a result, the storage utilization is reduced to a great extent, almost comparable to Quest LiteSpeed with a considerable backup and restore throughput. Moreover, the advanced features available with NetWorker Management Console make it a powerful tool to manage and schedule the backups. Applied Technology 14
References Product documentation For additional information, refer to the following documents available on Powerlink : EMC Backup and Recovery for Microsoft SQL Server Enabled by EMC NetWorker Module for SQL Server Proven Solution Guide EMC Backup and Recovery for Microsoft SQL Server Enabled by Quest LiteSpeed Proven Solution Guide EMC Backup and Recovery for Microsoft SQL Server Enabled by Microsoft SQL Native Backup Proven Solution Guide Applied Technology 15