1. Goal of this Paper
This paper sets out to be informative and educational in describing a number of solutions for protecting and recovering Microsoft Exchange installations. The challenges associated with protecting an Exchange environment, as well as multiple strategies that address them are covered in an easy to comprehend format. Upon completion of reading this paper, the reader should be well positioned to describe available data protection solutions for Microsoft Exchange as provided by NetBackup, the NetBackup for Exchange Server agent, and the NetBackup Snapshot Client.
1.1. Intended Audience
Anyone looking for information surrounding NetBackup and data protection solutions for Microsoft Exchange is encouraged to read this paper. Those with limited exposure to or experience with data protection solutions for Exchange will benefit from the content presented.
If you’ve ever asked any of the following questions, you are a member of the target audience for this paper:
- Is NetBackup able to recover individual mailboxes and recover mailbox items at a granular level?
- What value and advantage does NetBackup provide for Exchange that isn’t available otherwise?
- What advantage is there to using Volume Shadow Copy Service (VSS) snapshots?
- When should off-host backups be considered? 1
.2. Solution Overview
NetBackup provides a comprehensive data protection solution including centralized administration and reporting, media management, automated policy based backups, and restore. NetBackup for Microsoft Exchange Server extends the capabilities of NetBackup to include online backups and restores of Exchange databases. Additionally, NetBackup for Microsoft Exchange Server also provides a solution for protecting Exchange data at the mailbox level, facilitating granular recovery of mailboxes, messages, contacts, notes, tasks, and schedules.
An overview of the feature set provided by NetBackup for Exchange includes:
- Online backups
- Full, incremental, differential, and copy-only backups
- Redirected restores
- Individual mailbox backup with granular restore
- Integrated Snapshot Client support for VSS and off-host backups
1.3. Technology Issues Solved With These Solutions
Microsoft Exchange can be protected with the stock out-of-the-box “Backup” solution that is included with Microsoft Windows Server. “Backup” is also sometimes referred to as the “Windows Backup” program, or “NTBackup”. Limitations associated with the basic “Backup” solution are numerous. Specific to protecting and recovering Microsoft Exchange, there is no support for mailbox level protection, there is no support for VSS, and there is no support for off-host backups.
1.3.1. Granular Mailbox Protection
There are essentially two basic levels of Exchange protection available. The first is referred to as database level protection, where VSS compliant snapshots or the Exchange backup API are used to perform full or incremental database backups. These backups can be used to recover individual databases within an Exchange storage group, or an entire storage group. This method of backup is suitable for recovery from disasters or hardware failures.
The second basic type of Exchange protection is commonly referred to as a brick level backup. This type of backup uses MAPI (Messaging API) to protect Exchange mailboxes at a granular level. Mailbox backups are executed separately from Exchange storage group backups. Mailbox backups cannot be used to recover a database or storage group, but they can be used to recover individual mailboxes or mailbox content at a granular level. This method of backup is suitable for recovering accidentally deleted items.
Individual mailbox restores, or granular recovery of items within a mailbox isn’t supported by the Windows Backup utility. Microsoft does provide information detailing what a customer would need to do in order recover this data using what is referred to as recovery storage groups.
NetBackup for Microsoft Exchange server includes the ability to perform both storage group and brick level mailbox backups (dependant on the version of Microsoft Exchange being protected).
Additional mailbox protection and recovery information is included in Appendix I.
1.3.2. Volume Shadow Copy Services
Exchange Server 2003 introduced support for backup in conjunction with Windows Server 2003 VSS. With respect to Exchange, VSS acts as a mechanism for creating point-in-time copies of data that can be used for consistent Exchange storage group backup and recovery. Underlying VSS components are properly defined as providers, writers, and requestors.
Additional VSS information is available in Appendix II.
NetBackup incorporates support for VSS in conjunction with the Snapshot Client feature, detailed in a subsequent section of this paper.
1.3.3. Off-host Backup
Off-host backup with respect to Exchange refers to the ability to use a VSS compliant snapshot that has been mounted on an alternate host for the purpose of performing a storage group backup. The initial snapshot occurs on the Exchange server, and is then transported via a SAN or iSCSI network to an alternate host. The alternate host, for instance, may be a NetBackup media server. The VSS snapshot is used on the alternate host as source data for the Exchange backup. This methodology virtually removes any overhead induced by the backup process from the Exchange server, allowing users to send and receive e-mail without delays or being forced to wait longer for transactions to complete.
Off-host technology can be used in conjunction with performing full, copy, incremental or differential storage group backups. This solution requires use of the NetBackup Snapshot Client, and is supported for use in conjunction with NetBackup for Exchange.
2. Technology Overview
Protecting Microsoft Exchange includes backing up Exchange databases and log files. In addition to these items, data related to the Exchange installation should also be protected. Related data includes active directory information, certificate services data, system replication services data, system state data (including the IIS metabase), and any cluster information applicable to the Exchange installation. NetBackup provides a comprehensive set of data protection technologies which address the requirements and suggestions presented by Microsoft with regard to protecting Exchange environments.
2.1. Challenges Addressed with this Technology
Challenges in protecting and recovering Exchange are numerous. This subsection provides an overview of challenges and recommends solutions architected to overcome them.
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