Preparing for disaster recovery

Preparing for disaster ahead of time is key to recovering from it.

Overview

The first steps to recovery from catastrophic failure of an Exchange database or storage system should take place long before the event occurs.

Recommendations for disaster recovery preparation

Every environment and site is unique and every company has different requirements, depending on the amount of time recovery can take, archiving resources, and other factors. Taking these differences into account, consider the following general disaster recovery preparation recommendations:

If you are using SnapMirror to mirror your data, keep the storage system storing the destination SnapMirror volumes in a different physical location than your primary production system. In extreme cases, an entire site can be destroyed in a catastrophic event.
If you are using archiving, the archive media, such as a NearStore® system or tape, should be located off site.
Instate a policy of redundant knowledge by ensuring that more than one person knows how to restore the system.
Record your Exchange data configuration, and keep detailed records and logs of changes you make to your Windows and Exchange environments. Keep hardcopy duplicates of these records off site.

Components required to restore your environment

To be able to reconstruct your Exchange environment after a catastrophic failure, you must be able to recover the following three components:

Windows environment
You can either back up or replicate your Windows environment.

For more information about backing up your Windows environment, see Backing up your Exchange environment.

For more information about replicating your Windows environment, see Replicating your Exchange environment.
Exchange server
You can either back up your Exchange server or reconstruct it using the Exchange recovery mode. To be able to reconstruct your Exchange server, you must have restored or replicated your Windows environment exactly.

For more information about backing up your Exchange server, see Backing up your Exchange server.

For more information about replicating your Windows environment, see Replicating your Exchange environment.
Exchange data
You use SnapManager for Microsoft Exchange to create backups of your Exchange data, then move that data off site, either by archiving those backups or using SnapMirror to mirror them to another storage system at a remote site.

Two methods to get Exchange data off site

You can use either of these methods to get your Exchange data off site for disaster recovery:

You can use SnapMirror to mirror your storage system data to a storage system in another location.
For more information about using SnapMirror with SnapManager, see Using SnapMirror with SnapManager.
You can archive the data to physical media, such as tapes, and store that media off site.
For more information about archiving Exchange data, see Archiving SnapManager Backups.

If you're unsure which method to use, see the following table, which outlines advantages and disadvantages of each method:

Method to get Exchange data off site	Advantages	Disadvantages
Using SnapMirror	Restoring from a SnapMirror destination is significantly faster than restoring from tape. The destination can be updated more frequently than tape, resulting in more current archives.	Another storage system is required in the remote location. WAN connectivity to the remote location is required.
Archiving SnapManager backups	The required equipment might already be available and in use.	Restoring from tape is significantly slower than restoring from a storage system. Tapes must be stored and managed.

Backing up your Exchange environment

To be able to reconstruct your Exchange environment after a catastrophic failure, you must be able to restore both your Windows environment and your Exchange server.

Backing up your Windows environment

SnapManager for Microsoft Exchange, the Exchange server, and the storage systems are dependent on the Windows environment. Before you can use any of the processes in this section, the Windows environment must be completely restored. Therefore, it is important that you back up your Windows environment so that you can restore the same state as part of the recovery process.

To back up your Windows environment, you must complete, at a minimum, the following high-level process.

Task	Process
1	Back up your Exchange server, including your Windows operating system and any applications running concurrently with the Exchange server.
2	Use your backup utility to create and maintain a current emergency repair disk (ERD).

Backing up your Exchange server

To ensure that you back up all the required components on your Exchange server, follow the process outlined in the appropriate Microsoft document: Disaster Recovery for Microsoft Exchange 2000 Server.

Replicating your Exchange environment

If you want the ability to recover from a total site outage in a minimum amount of time, you can replicate your Exchange environment to a remote site. Then, if the primary site is destroyed, you can re-create your Exchange environment on the replicated site.

For more information about re-creating your Exchange environment on the replicated site, see Recovering a failed storage system and server to a replicated environment.

The following diagram shows a typical Exchange site replication:

Note the following facts about this site configuration:

The Windows environment (Active Directory, Domain Controller, etc.) is replicated through the Wide Area Network (WAN) to the replicated site.
For more information about replicating your Windows environment and using a replicated environment to recover from a disaster, see your Windows documentation.
The Exchange data on the storage system is mirrored using SnapMirror to a storage system on the replicated site.
For more information about setting up SnapMirror, see your Data ONTAP System Administration Data Protection Guide.
The standby Exchange server is configured identically to your primary Exchange server, except for the following differences:
- It does not yet have Exchange installed.
- It is not yet a member of the domain (leave it in workgroup mode).
- It has a different name than the primary Exchange server.