Exchange Server 2007: Design and Deploy Disaster Recovery Settings - Use Dial-Tone Restores

1/17/2011 2:41:54 PM
Problem : If your server goes down and you need to restore email functionality without the concern of previous mailbox data, is there some way to restore email to your users without worrying about the mailbox data until a later time? How would that be performed?

Solution : Because the mailbox itself is part of Active Directory and the actual mailbox data is within the Exchange databases, it is possible to restore an Exchange server quickly to the point of users having the capability to send and receive email again. This provides time for the actual database restoration to occur. This is called a dial-tone restore (also called the recover now, restore later method).

Some of the stress of this method comes from merging the two sets of data (the old recovered data with the new email sent back and forth in the dial-tone recovery database).

Keep in mind that there are several reasons to perform a dial-tone restore. One is that you have a failed server, and you need to use an alternate server for the restoration of email services. Another is that you simply have a failed or corrupt database that is just going to take too long to restore and your users need email now (so you might use the same server). You have to make some decisions regarding leaving the data on the recovery server or moving it back when the crisis is under control.

Perform a Dial-Tone Recovery on the Same Server

To mimic the failed database, you can dismount the database and locate the database file and delete it (or move it to another location). In Step 2, you create a new database, which does not require mailbox movements because this is the same server and storage group you are recreating. This gives you the time to recover the data to the RSG while your users have up-and-running mailboxes.

To achieve dial-tone recovery, perform the following:

If you have any log files from the failed database, you might want to move them to another location. They might be useful.

Open the EMC.

Attempt to mount the database and you receive the message shown in Figure 1 regarding the creation of an empty database. Click Yes to continue.

Figure 1. Warning message of an empty database.

From the Navigation Tree, expand the Toolbox work center.

From the options, open the Database Recovery Management tool.

Create a recovery group for the failed database.

Restore the backup you have of the failed database, but do not mount the database if you have any log files from the failed database. Place those in the proper location before mounting.

Mount the database from the task center.

From the task center, select the Swap Databases for Dial-Tone scenario.

Make sure the database is correct.

Select Gather Swap Information.

Select Perform Swap Action after confirming the information is accurate.

After the procedure is complete, the configurations for the original and recovery databases are swapped and remounted.

Swapping databases provides users the original mailboxes they had, but moves over the dial-tone database. The two should be merged to ensure no data is lost.

To do this, go back to the task center and use the Merge or Copy Mailbox Contents settings (just as you would with a normal recovery group) and merge that content over to the recovered and swapped database.

When you are done, remove the RSG.

Perform a Dial-Tone Recovery on a Different Server

The steps for a “new server” dial-tone recovery are almost identical to that of a “same server” dial-tone recovery. Here are some changes and additions:

  • You have to create a new storage group and database with the names of the original on the new server.

  • You need to use the Move-Mailbox -ConfigurationOnly command to point the user’s mailboxes to the new database. In doing this, you are moving the configuration information, but the data will be restored with the restoration process. The official command is:

    Get-Mailbox -Database <Mailbox Server Name\Storage Group
    Name\database name> | Move-Mailbox -ConfigurationOnly -TargetDatabase <Mailbox Server
    Name\Storage group
    Name\Dial Tone database

  • If you plan to restore your backup to the new server, the steps are the same as previously explained. If you plan to restore your backup to the failed server, you need to use the same EMS command to move the mailboxes back when you are done.


Users might be somewhat surprised when they have no email. However, they might be even more surprised if they have email but no access to all their messages. You will want to alert them with a message about what is happening. Some people receive a message that gives them the capability to see their old data if they have Outlook 2007 in cached mode. However, if they choose to use old data, they cannot send and receive. They will be presented with the option to use a temporary mailbox, and this is the option they need to select to send and receive messages.

  •  Exchange Server 2007: Design and Deploy Disaster Recovery Settings - Work with Recovery Storage Groups
  •  Exchange Server 2007: Design and Deploy Disaster Recovery Settings - Implement Database Portability
  •  Sharepoint 2007: Specify Your Colleagues
  •  Sharepoint 2007: Modify the Links in the SharePoint Sites Web Part
  •  Sharepoint 2007: Get Started with Your Personal Site
  •  Sharepoint 2007: Create a Personal Site
  •  Exchange Server 2007 : Backup and Recover Data (part 2) - Backup and Recovery with Server 2008
  •  Exchange Server 2007 : Backup and Recover Data (part 1) - Backup and Recovery with Server 2003
  •  Exchange Server 2007 : Design and Deploy Disaster Recovery Settings - Recover Deleted Items and Mailboxes
  •  Exchange Server 2007 : Design and Deploy Disaster Recovery Settings - Design for Disaster
  •  Architecting a SharePoint 2010 Deployment : Choosing the Right Hardware for SharePoint
  •  Architecting a SharePoint 2010 Deployment : Understanding the Reasons for Deploying Multiple Farms
  •  Understanding the SharePoint Server Roles
  •  Installing Exchange Server 2010 : Installing the Edge Transport Server
  •  Installing Exchange Server 2010 : Installing dedicated server roles
  •  Installing Exchange Server 2010 : Check the Exchange installation
  •  Introducing SharePoint 2010 (part 2)
  •  Introducing SharePoint 2010 (part 1)
  •  Installing Exchange Server 2010 : Unattended setup
  •  Performing a typical Exchange Server 2010 install
    Top 10
    Programming the iPhone : Progressive Enhancement - Location Awareness
    BizTalk 2006 : Implementing Dynamic Parallel Orchestrations
    Toshiba Portege Z830 - Flexi Thin
    Algorithms for Compiler Design: THE NFA WITH ∈-MOVES TO THE DFA
    Get Network Card Information
    XNA Game Studio 4.0 : Xbox 360 Gamepad (part 2) - Moving Sprites Based on Gamepad Input
    Windows Server 2003 : Clustering Technologies - Command-Line Utilities
    SQL Server 2005 : Basic OLAP - Building Your First Cube (part 1) - Creating the Project
    Password Hacks (Part 3) - Alternatives to passwords
    Lenovo Netbook Thinkpad X131e
    Most View
    Corsair Vengeance M90 - Play With A Vengeance
    Photoshop elements 9 : Add A Fisheye Effect To Shots In Elements
    Ditch your printer today : Step-by-step print your files to PDF (part 1)
    Adobe Illustrator CS5 : Proofing and Printing Documents - Using Spell Check, Using Custom Dictionaries
    iPhone 3D Programming : Textures and Image Capture - Texture Compression with PVRTC
    FXHome Hitfilm Standard
    Creating Link-Worthy Content and Link Marketing : Social Networking for Links
    Mindgenius 4
    SQL Azure : Tuning Techniques (part 4) - Indexed Views & Stored Procedures
    Sony Alpha NEX-7 (Part 3)
    SharePoint 2010 : Understanding Windows PowerShell Concepts (part 1)
    iPhone Application Development : Displaying and Navigating Data Using Table Views - Building a Simple Table View Application
    Men In Black 3, Jumping Knights
    Logisys Dracula VGA Cooler
    BizTalk 2006 : Implementing Dynamic Parallel Orchestrations
    Programming Microsoft SQL Server 2005 : The XML Data Type (part 1) - Working with the XML Data Type as a Variable & Working with XML in Tables
    IIS 7.0 : Using Command Line Tools - Working with Failed Request Tracing
    Biggest tips guide ever! (Part 3) - Security
    Windows Phone 7 Development : Push Notifications - Introducing the Push Notifications Architecture
    Programming with DirectX : Textures in Direct3D 10 (part 1) - Textures Coordinates