Backup and Recovery for Microsoft Exchange Server Best Practices with Data Domain

1.1 Background - Purpose and Scope
When it comes to backup, Data Domain storage systems provide unique and powerful disk-based solutions with high-speed inline data deduplication functionality that is perfect for simplifying backup and recovery solutions. The WAN-optimized replication capabilities of Data Domain storage systems provide an effective off-site alternative for DR scenarios as well. This paper focuses on backup and recovery of Microsoft Exchange systems and how to best leverage the capabilities of the Data Domain deduplication systems. Microsoft Exchange practices will be explored and mapped onto the specifics of the Data Domain solution as applicable.

1.2 Intended Audience
This paper is intended for solution architects and storage administrators involved in the planning and deployment of data protection solutions for Microsoft Exchange Server (2003 & 2007) environments using disk based or virtual tape technology. A familiarity with the Exchange architecture and basic backup and recovery practices is assumed.

1.3 Caveats
This paper focuses on the backup and recovery practices of Exchange environments utilizing the Data Domain solutions. It will not go into detail on Exchange primary storage layout unless it affects the practices described for the backup/recovery discussions.
There are many new features in Exchange 2007 that deal with availability and recovery mechanisms such as clustering and replication configurations. These will only be addressed as they relate to or affect the typical backup and recovery processes that most administrators face on a daily basis.
The information in this paper has been collected from several sources including Microsoft, several 3rd party backup solutions and other Data Domain technical papers. For the most current information please refer to your vendor’s specific solution or the links provided at the end of this document.

2 Best Practices Recommendations
The following is an overview of recommended best practices for a Microsoft Exchange backup and recovery with Data Domain. These specific recommendations will be covered in detail throughout the remainder of this paper.
Perform full backups whenever possible.
Size the Data Domain storage system for enough capacity and backup throughput to meet backup window and retention requirements for performing daily full backups.
Use a dedicated Exchange-aware backup application on a separate server to manage the backup operations.
Use the backup application’s Exchange API to get best data streaming results from the Exchange server to the backup server system or use the Exchange VSS capability to get the best volume based backup image.
Where possible, break down backup jobs first by ‘Storage Groups’ and then by databases within a Storage Group.
Direct backups from a Storage Group or database to the same Data Domain system if multiple systems are deployed.
Databases within a Storage Group should be backed up together to ensure the associated log file truncation is properly handled.
Use multiple streams to the Data Domain systems to improve overall aggregate backup throughput.
Limit the maximum number of concurrent backup jobs (streams) to approximately 10 per Data Domain storage system. The actual number depends on the structure of the Exchange configuration and the Data Domain system used – some smaller systems may be slightly lower, some larger systems may be slightly higher.
Increase the ‘Deleted Item Retention’ levels to allow for more recovery directly from the Exchange online databases. Analyze and plan the primary and backup storage accordingly for the potential increase in retained data.
Limit the amount of manual and automatic administrative actions (e.g., defragmentation, auto archiving, etc) that can regularly rearrange the internal Exchange databases.
This disrupts potential deduplication benefits as data sets are internally reorganized.
Do not use any form of compression settings within Exchange or the backup software application for data being sent to the Data Domain system.
Do not use any form of encryption settings within Exchange or the backup software application for data being sent to the Data Domain system.
Do not configure any form of multiplexing or stream interleaving.
Use more streams to disk targets. If VTL is used then allocate more virtual tape devices.
Do not perform any read back verification from the backup application during the backup operations.
Backup set verification can be performed after the backups have completed if necessary.
Tune the backup server buffer settings based on specific backup application recommendations and current Exchange environment resources.