Recovering from a disaster is a situation which every Administrator dreads. The fact that it happened in the first place is already bad, but with you being the one responsible for the organization's mail server, you'll be expected to get things up and running again in as little time as possible. Needless to say that, as soon as disaster strikes, the pressure is on! No one can predict when, if, or how it will happen, but taking measures to reduce the severity of the situation and being prepared is something you are expected to do.

This article is a follow on from Part 1 and helps you to understand what needs to be done to plan for a disaster and implement recovery methods.

Planning for a Disaster

If a disaster is going to happen, it will happen. If you are prepared for it though, you will give yourself a chance to limit the damage and get things up and running again in as short a time as possible. The key to success is a good recovery plan and below are some items to take into consideration:

1. Define the information that is necessary to backup, and do not take anything for granted.

2. Build an "emergency pack" or "crash cart" that contains the items needed to rebuild Exchange:

   • Windows Server and Exchange Server 2007 DVD-ROM and any related service packs

   • CD-ROM with hardware vendor device drivers

   • Product license keys and activation codes

   • Any Windows, Exchange and Hardware related documentation

3. Have documentation that contains at least the following:

   • The procedures for recovering each server role

   • Contact details of the person responsible for performing specific recovery tasks

   • Contact details of the person responsible for the decision to restore (if authority is required)

   • Contact details of the persons to be notified (at management level) in the event of a disaster

4. Ensure that your backups allow you to meet your Recovery Point Objectives and Recovery Time Objectives.

   Note: Recovery Time Objectives define the targeted amount of time it takes you to restore a service. For example, to bring a failed mailbox database back online you might have an RTO of 1 hour (this is where LCR comes in handy!).

5. Periodically test and verify your backups to ensure they can be restored correctly, and ensure that your transaction logs are easily available if you need to restore the last full backup.

Tips for Preventing a Disaster

Below are some steps you can take to help prevent or limit a disaster from occurring:

1. Check the Application and System Event Logs for clues. Investigate any warnings before they escalate into more serious issues.

2. Evaluate the possibility of implementing clustering, such as Continuous Cluster Replication, into your environment. This will provide automatic failover in the event that one of the servers goes down, making the failure invisible to end users.

3. When backing up data, choose a full backup whenever possible (as opposed to incremental).

4. Do not use circular logging on storage groups. Circular logging means Exchange will overwrite transaction log files after the data that the log files contain has been committed to the database.

5. Store backup copies off site. The last thing you want is for your backups to go down in flames, along with your production server.

6. Test your backups and verify their integrity. You do not want a situation where you go to restore a backup copy, only for it to be invalid.

7. Keep the database files on separate physical disks from the transaction logs.

Recovering Exchange Mailboxes and Mailbox Items

It may be the case that when an employee leaves the company, you delete the mailbox, only for a week or two later someone from Human Resources to tell you that they need to recover certain emails or that the employee is coming back. Exchange Server 2007 has, by default, a retention period of 30 days for deleted mailboxes.

When you remove or disable a mailbox, this continues to be available under Recipient Configuration | Disconnected Mailbox until you re-connect or permanently delete it.

To re-connect a disconnected mailbox and associate it with a user, do the following:

1. From Recipient Configuration | Disconnected Mailbox right click on the mailbox you want to re-connect and select Connect... to bring up the Connect Mailbox wizard. This is similar to the wizard for creating new objects, and first asks you to choose a mailbox type. We'll choose User Mailbox and click the Next button.

2. At the Mailbox Settings page, select the user to which you wish to connect the mailbox. Choose Matching user to have Exchange try to locate a matching user in Active Directory. If a matching user cannot be found, choose Existing user to connect the mailbox to another user object of your choice. In this example, I have re-created the user previously deleted.

3. Next, confirm the details of the configuration and press the Connect button.

The corresponding cmdlet for this operation is Connect-Mailbox. Below is an example of the cmdlet used to re-connect Raymond Spiteri's disconnected mailbox:

Connect-Mailbox -Identity '<UserAccountGUID>' -Database 'mx2007.testdomain.local\First Storage Group\Sales' -User 'testdomain\rays' -Alias 'rays'

Where <UserAccountGUID> would be replaced by the Active Directory GUID of the user account.

You may also find that a user has inadvertently deleted an e-mail and cleared the Deleted Items folder and now needs a way of bringing this e-mail back. When an item is deleted, it goes to the Deleted Items folder, and when cleared from the Deleted Items folder, it is moved into the Deleted Items cache. The default retention period for deleted items within this cache is 14 days. Once this retention period has expired, items are permanently deleted as part of the mailbox database's online maintenance.

Both these options are configurable from Mailbox Database Properties | Limits property page.

To recover items from the Deleted Items cache, a user can select Tools | Recover Deleted Items from within Microsoft Outlook. This will launch the Recover Deleted Items dialog. From here you can select the item you want to recover and click on the Recover Selected Item button. When an item has been recovered, it will be placed back into the Deleted Items folder.

Restoring a Local Continuous Replication (LCR) database

If you notice that your production database is corrupt, you can manually restore the LCR copy as follows:

1. Dismount the mailbox database from the Exchange Management Shell. Under Server Configuration | Mailbox, right click on the mailbox database for the respective storage group at the bottom right and select Dismount Database.

   The corresponding cmdlet for this operation is Dismount-Database "Database Name".

2. Right click on the storage group and select Restore Storage Group Copy (as shown in the image below). This will bring up the Restore Storage Group Copy wizard.

   

3. At the first wizard page confirm the storage group name and choose whether to check the "Replace production database path locations with this copy". This option will swap the database path locations of the backup copy with the original production copy. The corresponding cmdlet for this option is Restore-StorageGroupCopy "Storage Group Name" -ReplaceLocations.

4. On the next page, click the restore button and allow the operation to complete. Once it does, it will confirm the result in the summary section within the wizard (as seen in the image below). Press Finish to close the wizard.

   

5. The database can now be remounted by right clicking on the database name and selecting Mount Database. Alternatively, you can use the cmdlet Mount-Database "Mailbox Database Name".

Restoring Exchange using the Windows Backup Utility

In part 1 of this series, I demonstrated how to backup an Exchange database and the respective Exchange Server files and folders into a Backup Utility file (BKF). Here, we look at how to restore that file using the Windows Backup Utility.

1. Open the Windows Backup Utility by either navigating to Start | Programs | Accessories | System Tools | Backup or typing ntbackup.exe in the Run window and pressing the return key.

2. Click the Restore and Manage Media tab and select the media set you want to work with from the right hand pane. Note that you can optionally select individual items to restore from each Storage Group.

   

3. Next, press Start Restore and the Restoring Database Store dialog will popup asking where the backups should be restored to and a temporary location for log and patch files to be placed. Once you have entered the necessary details, click OK for the restoration process to start.

4. Once the restore is complete, you can check click the Report... button and look at the Application Event Logs for more information (and to troubleshoot any issues that may have occurred during the restore process).

Conclusion

In this article we looked at the recovery aspects of the Exchange 2007 backup and recovery process. We went over some considerations for creating a recovery plan and steps you can take to help prevent or limit a disaster, as well as a walkthrough of how to restore an LCR database and an Exchange Server backup using the Windows Backup Utility.

References

How to Connect a Mailbox

Configuring Deleted Mailbox and Deleted Item Retention