EMC Solutions for Backup to Disk EMC Celerra LAN Backup to Disk with Symantec Backup Exec Best Practices Planning

Transcription

1 EMC Solutions for Backup to Disk EMC Celerra LAN Backup to Disk with Symantec Backup Exec Best Practices Planning Abstract This white paper describes how to configure the Celerra IP storage system for optimal performance when used as a backup target with Symantec Backup Exec for Windows Servers. November 2007

2 Copyright 2007 EMC Corporation. All rights reserved. EMC believes the information in this publication is accurate as of its publication date. The information is subject to change without notice. THE INFORMATION IN THIS PUBLICATION IS PROVIDED AS IS. EMC CORPORATION MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WITH RESPECT TO THE INFORMATION IN THIS PUBLICATION, AND SPECIFICALLY DISCLAIMS IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Use, copying, and distribution of any EMC software described in this publication requires an applicable software license. For the most up-to-date listing of EMC product names, see EMC Corporation Trademarks on EMC.com All other trademarks used herein are the property of their respective owners. Part Number H Best Practices Planning 2

3 Table of Contents Executive summary...4 Introduction...4 Audience... 4 Terminology... 4 Overview...5 Celerra architecture... 5 Data Mover... 5 Control Station... 5 Storage system... 5 Network... 6 Celerra data protection... 6 Celerra Replicator... 6 Disk-based backup solution...6 Backup-to-disk solution overview... 6 Backup performance... 7 Recovery... 7 Multistreaming... 7 Media reliability and data availability... 7 Overall IT efficiency... 7 Symantec Backup Exec...7 Symantec Backup Exec for Windows Servers... 7 Small Business Server Edition (SBSE)... 7 Symantec Backup Exec licensing... 8 Architecture of Symantec Backup Exec backup-to-disk... 9 Backup and restore methods... 9 Backup methods... 9 Restore methods Implementation...10 Celerra configuration steps Symantec Backup Exec planning Backup Exec backup sequence Backup Exec restore sequence Recommendations...19 Celerra configuration CLARiiON array configuration settings Symantec Backup Exec settings and considerations Network settings Conclusion...21 References...21 Best Practices Planning 3

4 Executive summary Disk-based data protection solutions have become desirable and affordable because of the lower cost of ATA storage systems. As a complement to using tape for long-term storage, backup to disk (B2D) is a powerful solution for rapid recovery of mission-critical data, and it yields significant benefits over traditional backup to tape. This paper discusses the advantages of backup to disk and outlines best practices for using and configuring Symantec Backup Exec for Windows Servers software with a Celerra IP storage system as the backup-todisk target for Windows clients. Introduction The guidelines in this paper consist of configuration and parameter settings for the Celerra IP storage system, the Symantec Backup Exec backup server, and the backup client. It describes the Celerra architecture and the replication data protection feature available on the Celerra. With the steps outlined herein, setting up the environment for backup and restore operations is simple and quick. Audience The intended audience is IT planners, storage architects, and storage and backup administrators who are involved in IT backup strategies or who seek a context for the implementation and configuration of their backup-to-disk solutions using an IP network. Terminology ATA: Advanced Technology Attachment. ATA Enclosure: CLARiiON disk-array enclosure with ATA disks. AVM: Automatic Volume Management. LAN: Local Area Network. Link Aggregation: A high-availability feature based on the IEEE 802.3ad Link Aggregation Control Protocol (LACP) standard enabling Ethernet ports with similar characteristics to combine into a single virtual device/link with a single MAC address and potentially multiple IP addresses. LUN: Logical Unit Number. The identifying number of a SCSI object that processes SCSI commands. The LUN is an ID for the logical unit, but the term is sometimes used to refer to the logical unit itself. MVM: Manual Volume Management. NAS: Network-Attached Storage. NIC: Network Interface Card. NDMP: Network Data Management Protocol. QoS: Quality of Service. RAID 5: Data is striped across disks in large stripes. Parity information is stored so that data can be reconstructed if needed. One disk can fail without data loss. SAN: Storage Area Network. SPE: Storage Processor Enclosure: The chassis element containing the storage processors, power supplies and fans. Host and Fibre Channel ports are located on the SPE. It has dual-shared power supplies and is always powered by a standby power supply. WAN: Wide Area Network. Best Practices Planning 4

5 Overview The following sections are an overview of the Celerra architecture and data protection. Celerra architecture The Celerra is a network-attached storage server that enables clients on a network to store and retrieve files over the network. Dedicated file servers, like Celerra, offer high availability and disaster recovery options that are not commonly available with general-purpose servers. Backup operations can be done with little or no interruption to production file access. By making backups easier to manage, they are more likely to be performed on a regular basis. The Celerra is made up of several key components the Data Movers, Control Station, storage system, and network. Additionally, the Celerra is available in two distinct configurations: integrated and gateway. The Celerra integrated platform is comprised of one or more Data Movers and a dedicated storage processor enclosure (SPE). The SPE manages the back-end CLARiiON storage system. The gateway Celerra is also comprised of one or more Data Movers and connects into an existing SAN storage system. Data Mover The Data Movers move data between the storage system and the client computer. Administrators typically do not manage Data Movers directly, but work with the Control Station that in turn sends commands to the Data Mover. A Data Mover can be active or a standby for other Data Movers. Each Data Mover is independent; there is no communication between Data Movers. If a Data Mover fails, the Control Station manages the failover to the standby Data Mover, assuming a standby has been configured. Each Data Mover is connected to the storage system, Control Station, and network. Control Station The Control Station is a dedicated management computer that monitors and sends commands to Data Movers. It connects to each Data Mover and to the storage systems through the Data Movers. The Control Station can be connected to a public or private network for remote administration. After the Data Movers are booted, they do not depend on the Control Station for normal operation. In the unlikely event the Control Station fails, the Data Movers continue to serve files to clients. Storage system The storage system is an array of physical disk devices used by the Celerra. It contains one or more disk arrays. The storage system stores and retrieves blocks of data for the Data Movers and is made up of Fibre Channel or serial-ata disks. In a backup-to-disk environment, data is stored on serial-ata disks. The Celerra system offers two options to allocate and manage the storage system: Automatic Volume Management (AVM) The AVM feature automatically creates and manages usable file system storage. File systems are created using system-defined or user-defined storage pools. System-defined storage pools are dynamic by default, and AVM adds or removes volumes automatically from the storage pool as needed. Manual Volume Management (MVM) MVM provides additional flexibility in creating and aggregating different volume types into usable file-system storage that meets required configuration needs. Creating and managing volumes manually provides greater control over the location of storage allocated to a file system. There are a variety of volume types and configurations from which to choose to optimize a file system s storage potential. Volumes can be divided, combined, and grouped to meet specific configuration needs. Best Practices Planning 5

6 Network The network enables clients to communicate with the Celerra. Each Data Mover has its own set of network connections. There are also network connections between the Data Movers and the Control Station. Each Data Mover has one or more network interface cards (NICs). Celerra data protection This white paper describes a LAN backup-to-disk environment with a client/server model where the primary data is located on a Windows client and a backup server functions as the administrator and manager of the backup procedure. The backup process stores the data in a Backup Exec folder mapped to a CIFS share on serial-ata disks connected to the Celerra rather than on a tape drive connected to the backup server. The client data backed up to the Celerra can be further protected with the Celerra Replicator feature available on the Celerra. Celerra Replicator The Celerra Replicator is a powerful, easy-to-use asynchronous replication solution that creates a point-in-time copy of a Celerra file system. The Celerra Replicator is optimized for WANs and its management is fully integrated in to the Celerra Manager. It was designed with disaster recovery in mind, and provides capabilities such as failover, reverse replication, incremental resync, and others. Data backed up to a Celerra can be replicated to a secondary Celerra for further protection and offsite storage. Disk-based backup solution This section provides an overview of a backup-to-disk solution and a description of the Symantec Backup Exec backup-to-disk architecture. It lists different methods available when performing a backup or a restore and provides a sequence of steps to perform backup and restore functions. Backup-to-disk solution overview Traditionally, tape has been the cornerstone of backup and archiving strategies. Tape has become entrenched in the minds of IT decision makers as a symbol of data safety. If your data was on tape, it was presumed safe. Dislodging the incumbent solution would take a significant shift in the underlying assumptions. The emergence of serial-ata disk drives provided that shift. Disk-based data protection solutions have become desirable and affordable because of the lower cost of ATA storage systems. As a complement to using tape for long-term storage, backup to disk is a powerful solution for rapid recovery of mission-critical data, and it yields significant benefits over traditional backup to tape with the promise of the following: Fast backups Rapid restores Near-term recovery of mission-critical data Greater reliability and predictability of the backup medium Significantly enhanced business continuance Disk-based backups do not replace tape, but instead shift tape into an archival role. Today, EMC recommends adopting a backup-to-disk solution when backup and restore performance and data reliability are primary concerns. Best Practices Planning 6

7 Backup performance Symantec Backup Exec users can back up data at the write speeds of the Celerra storage systems. Additionally, disk drives are random access devices and can immediately start writing data. Tape technologies require positioning and respond to a minimal data stream by shoe-shining or excessive back and forth positioning. The shoe-shining motion necessary to position a tape is detrimental and causes tapes to wear out. Recovery Data is recovered at the processing speed of the Celerra storage systems and is read in a contiguous manner that enables users to gain the benefits of protecting clients in parallel without sacrificing recovery performance. Tape mounting and unmounting delays are also eliminated. As a result, Symantec Backup Exec users experience significant improvement in recovery time from disk as compared to tape. Multistreaming Multistreaming improves aggregate performance by being able to read and write multiple streams of data to and from the same file systems simultaneously. Media reliability and data availability Media-specific errors, including faulty tape media and tape mounting failures, that can cause backups to fail are minimized. Disk-system RAID protection ensures data availability in the event of a disk drive failure. As a result, fewer full backups may be required that would save network and CPU-processing cycles. Overall IT efficiency Tape handling is reduced or eliminated. Maintaining a set of tapes from tape libraries can be problematic and requires properly trained personnel. Disk does not require tape handling and positioning. Backup to disk also provides the ability to perform both backups and restores at the same time. Symantec Backup Exec Symantec Backup Exec for Windows Servers is a high-performance data management solution for Windows server networks. With its client/server design, Backup Exec provides fast, reliable backup and restore capabilities for servers and workstations across the network. Backup Exec is available in configurations that can accommodate multiplatform networks of all sizes. The following sections describe the Symantec Backup Exec editions. Symantec Backup Exec for Windows Servers This application installs on and protects Microsoft operating systems. The Backup Exec suite includes agents and options for backing up and restoring data on heterogeneous networks of all sizes. The Backup Exec workstation agent software protects unlimited remote workstations running on Windows XP Professional, Windows 2000 Professional, Windows Me, and Windows 98. Stand-alone tape drives are supported. Backup Exec also includes support for a single drive robotic library. To enable support for additional robotic library drives, you must purchase the Library Expansion option. Small Business Server Edition (SBSE) This application supports Microsoft Small Business Server for Windows (Server 2005, 2003 or Windows 2000) and Standard Edition operating systems. SBSE also includes Backup Exec agent software for Best Practices Planning 7

8 workstations running on Windows XP Professional, Windows 2000 Professional, Windows Me, and Windows 98. The following is a list of the Backup Exec agents and options: Exchange agent SQL agent Intelligent Disaster Recovery option Advanced Open File option Desktop and Laptop option SBSE can be purchased with the following options: Library Expansion option Remote Agent for Windows and NetWare systems Symantec Backup Exec licensing License keys are required to install Backup Exec and its options. Table 1 shows the features available for installation with the Backup Exec license key. Table 1 Feature Installation features available with license key Description Tape device drivers Online documentation Robotic library support Symantec tape device drivers for all supported tape devices that are attached to the server. Symantec Backup Exec Release 11d Administrator s Guide Enables support for multi-drive tape or optical robotic libraries and library storage systems. Tivoli Storage Manager option Enables the TSM server s storage resources to appear as a tape robotic library in a list of target devices on the Backup Exec server. Backup Exec administrators can then direct the output of any Backup Exec job to the TSM server by selecting the name of the TSM robotic library as the destination when submitting the job. Create clone CD-ROM image Captures the Backup Exec installation program and your installation settings such as account information, additional options, and destination directory. After the clone CD-ROM image has been created, it can be copied to a CD-ROM. You can then use that CD-ROM to install Backup Exec on additional servers using the same settings. Copy server configurations Enables copying of server configurations, login account information, jobs, policies, and selection lists to remote media servers. This feature is selected automatically if a CASO license key has been entered. DLO (support for 5 users included with Backup Exec) Enables up to five desktop users to install the Desktop agent for free automated file protection. Managed media server Makes a stand-alone media server into a managed media server that is controlled by the central administration server. You cannot select this feature if you entered a CASO license key. All other options and agents require the purchase of additional licenses. Installing an evaluation version enables many options that must be purchased separately. Best Practices Planning 8

9 Architecture of Symantec Backup Exec backup to disk There is no standard language when it comes to backup, and backup vendors vary when it comes to terminology. Regardless of the terminology, all vendors provide a similar client/server model. The major components in Symantec Backup Exec terminology are the following: Backup Exec client. Primary data is owned by this system. The client could be an application server, a file server, a desktop, or a laptop. A software agent is required on all Backup Exec clients. Backup device. The device where backup data is stored. For Celerra backup to disk, the backup device is ATA disks. Backup Exec media server. The server with the Backup Exec server components that processes all backup or restore jobs. When a backup takes place, files identified for backup on the Backup Exec client are transmitted over the network to the media server. The backup device, located on the Celerra, appears as a folder on the media server. Likewise, when a restore operation takes place, the files identified for restoration are transmitted over the network from the Celerra to the media server and then to the Backup Exec client (Figure 1). Figure 1 Backup and restore topology Backup and restore methods These sections describe the backup and restore methods for Symantec Backup Exec. Backup methods The following methods are available for backup to disk: Backup Wizard: The wizard steps you through the process of creating a backup job using mostly default options. Best Practices Planning 9

10 Backup job properties: Customized backup jobs can be created by setting backup options such as job priority (which is not available in the wizard). Selection list: Data to be backed up can be selected and saved as a selection list. This list can be selected when creating one or more backup jobs. The selection list can also be combined with a policy to create a job. Backup Exec Windows Explorer interface: Files and folders can be selected from Windows Explorer without the need to launch the Backup Exec Administration Console. Restore methods The following methods are available when restoring from disk: Restore Wizard: The wizard steps you through the process of restoring data. Job properties: Data can be restored based on properties defined during the restore job process. For instance, data can be restored to a system different from the one where the data was backed up. Implementation The Celerra is not aware that a backup to disk is in progress. From the Celerra point of view, it is simply providing a target file system for the requesting application. The Celerra system administrator must create one or more file systems containing the backup folders for use by the Backup Exec application. The configuration described in this paper is for a Celerra with a single ATA enclosure and a Celerra with two ATA enclosures. The following sections describe: How to configure the Celerra and the Symantec Backup Exec software in a backup-to-disk environment. How to plan a backup strategy prior to configuring the media server or clients. How to back up client data to the Celerra. How to restore data from the Celerra to a client. Celerra configuration steps As a target for a backup-to-disk application, a Celerra can be configured with a full shelf of ATA disks or a partial shelf of disks. The configuration steps highlighted in this section are for a Celerra configured with two disk shelves, one partially populated and one fully populated. The example uses the clarata_archive AVM storage pool and creates 4+1 RAID 5 groups. The clarata_archive storage pool was setup during the initial Celerra installation to utilize 4+1 RAID 5 groups. If the ATA disk shelves are fully populated, the clarata_archive storage pool can be setup to utilize 6+1 RAID 5 groups during initial installation. For more information regarding initial storage configuration, please refer to the Celerra Network Server Phase 3 Setup Guide. RAID 5 configurations stripe data and parity across all the disks. Table 2 shows an example using 500 MB disks configured as RAID and 6+1 and the approximate amount of usable disk capacity and parity usage. Table 2 Disk Size RAID 5 capacity planning Disk Group Type Number of Disks per Group Type Approximate Data Capacity Approximate Parity Usage 500 MB MB 500 MB 500 MB MB 490 MB Best Practices Planning 10

11 The Celerra system administrator must create one or more file systems containing the backup-to-disk folders for use by the Symantec Backup Exec application. The following configuration steps are for a Celerra with one ATA enclosure and a Celerra with two ATA enclosures. The single ATA enclosure configuration contains 11 disks. In the dual enclosure example, the first enclosure contains 12 disks while the second enclosure contains 15 disks. Celerra s automatic volume management is used to create the file systems. A single file system is created in the single ATA disk enclosure configuration while two file systems are created in the dual ATA disk enclosure configuration. All Celerra configuration steps are performed using the Celerra Manager interface. 1. For single and dual ATA enclosures, perform the following steps: a. Create a CIFS server using the Celerra Manager Wizard. i. Select Wizards from the Celerra Manager navigation pane. ii. Select Create a CIFS Server. iii. The Celerra Manager Wizard provides all necessary instructions for creating a CIFS server. b. After creation of the CIFS Server, select Create a CIFS Share from the Celerra Manager Wizard menu. i. The first option is to select the CIFS Share Location. Choose the option By selecting a file system first. ii. Select the default Data Mover. iii. Select Create File System. 1. Select the same Data Mover as in step ii. 2. Select Storage Pool. 3. Select the clarata_archive Storage Pool. This storage pool automatically creates two 4+1, RAID 5 groups and one hot spare. 4. Enter a name for the file system. 5. Enter the size of the file system. 6. All remaining screens are optional. Click Next on each screen or enter desired information. iv. After the file system is created, the Wizard returns to the CIFS Share creation. v. Select the file system created previously. vi. Select the CIFS server created previously. vii. Enter a CIFS Share name. Best Practices Planning 11

12 viii. Click Finish. For a dual ATA enclosure, select Wizards again and create a second CIFS Server, file system, and CIFS share. See the previous procedure. Upon completion, the dual enclosure disk layout contains the following RAID 5 groups: Enclosure 1: Two 4+1 RAID 5 groups and two hot spare disks Enclosure 2: Three 4+1 RAID 5 groups Symantec Backup Exec planning Prior to configuring the media server or the clients, the Backup Exec Administrator s guide recommends that the system administrator perform the following planning steps. Ensure the storage devices are connected and configured correctly. Decide where the backup folders will be located. Understand how Backup Exec provides overwrite protection for your media. Decide which Windows credential the Backup Exec logon account will use when browsing and making backup selections. When starting Backup Exec for the first time, default configuration options are in effect. Backup and restore jobs run safely with the defaults. The defaults can be changed at a later date. The following configuration options are a subset of all options available with Backup Exec. They are listed here because of their importance when planning a backup strategy for disk space and network requirements. 1) Plan the backup method for the files. The options include: Full: Includes all the data that was selected for backup. Incremental: Includes only the files that have changed since the last backup. Working Set: This method includes two options: Changed today and Last accessed in X days. Changed today: Files are backed up with today s date. Last accessed in X days: Includes data that has been accessed in a specific (X) number of days. 2) Plan the backup compression type: Backup Exec can perform software, hardware, or no compression. To maximize the amount of backup data stored on a disk, use the software compression option. Backup Exec backup sequence All Backup Exec functions are submitted using the Administration Console installed on the media server. To perform a backup operation using the Symantec Backup Exec software, do the following steps: Best Practices Planning 12

13 Figure 2 Create a backup-to-disk folder 3) Create one or more backup-to-disk folders using the device configuration wizard as shown in Figure 2. A backup-to-disk folder is a virtual device that Backup Exec treats the same as a real device. When you create a new backup-to-disk folder, Backup Exec automatically assigns the name Backupto-Disk Folder X where X is a number incremented by one each time a new backup-to-disk folder is created. The default folder name can be changed anytime. The backup-to-disk folders map to CIFS shares on the Celerra. Best Practices Planning 13

14 Figure 3 Select a backup set value 4) Select a backup set value as shown in Figure 3. The value represents the maximum number of backup sets to be written to each backup-to-disk file in this folder. Fewer backup sets in a backup-to-disk file may enable the overwrite protection period to expire sooner, and disk space to be reclaimed faster. Best Practices Planning 14

15 Figure 4 Create a backup job and priority 5) Create a backup job and set the job priority using the backup wizard as shown in Figure 4. Optionally, create a schedule to define when the job will run. The schedule option enables you to configure the time and the frequency for when the job runs. During the job setup, you can choose to run the job immediately, once on a specified day and time, or according to a schedule. The highest priority job is backed up first. Best Practices Planning 15

16 Figure 5 Backup job status 6) Monitor status and throughput from the Job Monitor tab as shown in Figure 5. Best Practices Planning 16

17 Backup Exec restore sequence All Backup Exec functions are submitted using the Administration Console that is located on the media server. To perform a restore operation using the Symantec Backup Exec Restore Wizard, do the following steps: Figure 6 Restore Wizard 1) From the Restore Wizard, select files or directories to be restored as shown in Figure 6. Best Practices Planning 17

18 Figure 7 Restore schedule 2) Determine whether the restore is to take place immediately or at a later date and time as shown in Figure 7. Best Practices Planning 18

19 Figure 8 Restore job status 3) Monitor status and throughput from the Job Monitor tab as shown in Figure 8. For more information, refer to the Symantec Backup Exec Release 11d Administrator s Guide. Recommendations The following sections provide configuration recommendations for the Celerra system, the network, and Symantec Backup Exec, and general recommendations regarding backup to disk. Celerra configuration Consider the following Celerra configuration guidelines to ensure optimum backup-to-disk performance: Minimum Celerra version 5.5 or later. Minimum FLARE version Release 22 or later. File-system layout In a backup-to-disk environment, Celerra 5.5 supports up to file systems 16 TB and a maximum of 32 TB of physical storage per Data Mover. Resource allocation from advanced features such as Celerra Replicator must be taken into consideration when evaluating backup-to-disk performance requirements. Performance could be impacted if Celerra Replicator is running in the background while a backup is taking place. Set the Celerra cifs.prealloc parameter = 6. When a CIFS client wants to write data, it asks the file server if there is enough space to write one byte of data (regardless of how much it wants to write). The file server then responds with an Best Practices Planning 19

20 amount of data the client can write before it must ask again (the prealloc size). The larger the prealloc size that the file server returns to the client, the less often the client has to ask the question. Fewer questions mean better performance. Allocation size is computed from a virtual block size allocation and real file size. A crucial component to making a backup-to-disk decision is determining how much disk capacity is required to hold all the data to be backed up. Many factors play into this decision. The following are a few considerations. The amount of source data to be backed up. Backup method: Full or incremental. If full backups are performed regularly instead of incremental backups, more disk space is required to accommodate the volume of data. Backup frequency: For example, more disk space is required if full backups are performed daily rather than weekly. Backup retention: How long will backup data be kept on disk prior to being deleted or moved to alternate storage for longer retention? The longer the data is kept on disk, the more disk capacity is required. Disk volume configuration: When using RAID 5, approximately 20 percent of the total disk capacity is allocated to parity data. The parity information provides protection should a disk failure occur. CLARiiON array configuration settings Use the settings in Table 3 to configure the CLARiiON storage array in a backup-to-disk environment. Table 3 CLARiiON array cache parameters for backup to disk Cache parameter Write cache Read cache Cache page size Value Maximum allowed Remaining memory 16 KB for larger I/Os Symantec Backup Exec settings and considerations The following describes the Backup Exec settings and best practices: Minimum Symantec Backup Exec version Backup Exec 11d or later. Backup Exec server Select appropriate hardware for the Backup Exec server as recommended in the Backup Exec administrator s guide. Avoid running disk-intensive applications, such as virus scanning, on the backup client when it is backing up or restoring files. Source data If the source data is located on a single, non-raid, physical disk and multiple backup streams are running in parallel, the source physical disk could become a performance bottleneck because of parallel reading. Therefore, only run a single backup stream on Backup Exec clients where the data to be backed up is on a single physical disk. Backup Exec provides the Advanced Open File option for handling open files during a backup. When this option is installed, it can be configured to back up files that are closed within a certain number of seconds. If this option is selected, Backup Exec waits the specified time interval for files to close before skipping the open file and continuing the backup operation. If the file does not close during the specified interval, it is skipped. A listing of skipped files appears in the job log for the backup. If multiple files are open, Backup Exec waits the specified time interval for each file. Depending on the number of open files, this may significantly increase the backup time. Therefore, reduce the Best Practices Planning 20

21 time interval when using the Advanced Open File option and when high numbers of open files are expected. Network settings Network performance is key to achieving optimum performance. The network must be tuned to avoid congestion and to guarantee that the backup window is not limited by network bandwidth. Use a dedicated backup network by configuring a separate network or through the use of QoS features that guarantee network bandwidth. If supported, enable jumbo frames on the backup client and the Celerra to enhance performance. Use link aggregation on the Celerra to increase the link speed beyond the limits of a single Ethernet port. EMC recommends using all available Gigabit Ethernet ports on the Data Mover in a link aggregation trunk for maximum throughput. Conclusion With these practices, optimum performance can be achieved using a Celerra system for backup to disk with Symantec Backup Exec. References The following documents provide additional, relevant information. Access to these documents is based on your login credentials. If you do not have access to the content listed below, contact your EMC representative: Celerra Network Server Concepts Guide (available on Powerlink ) Configuring CIFS on Celerra (available on Powerlink) Symantec Backup Exec 11d for Windows Servers Administrator s Guide EMC Solutions for Backup to Disk Reference Architecture EMC Solutions for Backup to Disk Validation Test Report (available on Powerlink) Best Practices Planning 21