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The most common challenge that Exchange Server administrators experience while repairing the Exchange database is the situation of a downtime. It can hamper the productivity and efficiency of the organization. Dial tone recovery in Exchange 2013/2016 appears as a savior in such cases, as it allows continuing email communication with its dial tone portability feature where it replaces the original database with an empty database. This temporary empty database is the dial tone database.
What is Dial Tone Portability?
Dial tone portability essentially involves setting up a temporary mailbox for users to send and receive emails when their original mailbox is being repaired or restored. This feature is extremely valuable for businesses as it ensures uninterrupted email communication during Exchange Server failures or database issues.
You can create a temporary mailbox on the same server or on another server within your organization, as long as these servers have databases with matching database schema versions. The Autodiscover feature automatically redirects clients to the new database without requiring manual intervention. As an administrator, after successfully restoring the user’s original mailbox, you can merge the recovered mailbox with the dial tone mailbox.
Dial Tone Recovery – Exchange Server 2013/2016
In dial tone recovery, an empty database is created on a mailbox server, and the failed database is replaced with it. The empty database that you create is referred as dial tone database through which you can send or receive messages while your original database is being repaired.
Performing Dial Tone Recovery
Exchange dial tone recovery is efficient at providing support as uninterrupted communication flow even while the Administrator account is corrupted. Users can regain control of the original database for sending and receiving emails once the database recovers.
The prerequisites for executing the dial tone recovery in Exchange Server 2013/2016 are:
- The user must have Organization Management permissions on mailboxes
- Must have a smaller number of databases on the server than the maximum allowed
Info: Exchange 2013/2016 Standard Edition supports up to five databases per server.
How to Perform Dial-tone Recovery on a Single Server?
Before you begin, take backups of your database to have them so that if you need those files in the future, you can access them as required.
- Renaming of the existing database folder
To rename the existing database folder, follow the given instructions.
- Login to Exchange Server with Admin-level permissions.
- Press the Windows key + R to open the run window, type services.msc and click OK.
- Halt the below services from running:
- Microsoft Exchange Search Service.
- Microsoft Exchange Search Host Controller Service.
- Microsoft Exchange Information Store Service.
- In the corrupt EDB folder, rename the EDB folder to NAME_old and the log folder to NAME_Logs_old.
- Now, start all three services again.
- Start Exchange Management Shell and run the given commands one-by-one:
- To create a dial tone database, run the command:
New-MailboxDatabase -Name <dial tone database name> -EdbFilePath <enter full EDB file location path>
- To reset the user mailboxes hosted on the database being recovered, run:
Get-Mailbox -Database <database name> | Set-Mailbox -Database <dial tone database name>
- Now, mount the database so that client computers can access the database, and send and receive the messages –
Mount-Database -Identity <dial tone database name>
- Create a recovery database using this command:
New-MailboxDatabase -Recovery -Name <recovery database name> -Server <server name>
Or
To create another recovery database on another server:New-MailboxDatabase -Recovery -Name <recovery database name> -Server <server name> -EdbFilePath “<full EDB file path location>” -LogFolderPath “<full log folder path location>” - Once the data is copied to the Recovery database, copy the log files from the failed database to the recovery database log folder so they can be played against the restored database.
First, mount the recovery database and then dismount it –Mount-Database -Identity <recovery database name>
Dismount-Database -Identity <recovery database name> - After dismounting the recovery database, move current database and log files residing in the recovery database folder to another secured location (it is a preparation step to swap recovered database with dial tone database).
- Now, dismount the dial tone database-
Dismount-Database -Identity <dial tone database name>
Now move database and log files from dial tone database to recovery database folder.
- Further, move the database and log files from the secured location to the dial tone database folder. Once moved, mount the dial tone database again –
Mount-Database -Identity <dial tone database name>
Now, users can access the original database and can send and receive messages.
- Once again, mount the recovery database-
Mount-Database -Identity <recovery database name>
- To export the data from the recovery database to recovered database, run the following commands-
$mailboxes = Get-Mailbox -Database <dial tone database name>$mailboxes | %{ New-MailboxRestoreRequest -SourceStoreMailbox $_.ExchangeGuid -SourceDatabase <recovery database name> -TargetMailbox $_ }
- Now, you can dismount and remove the recovery database-
Dismount-Database -Identity <recovery database name>
Remove-MailboxDatabase -Identity <recovery database name> - Verify the move
Now, to verify that your mailbox has successfully been moved, try to access the mailbox in Microsoft Outlook and Outlook for Web and check messages.
What to Do after Setting Up the Dial Tone Recovery?
The dial tone portability is just a workaround and not a fix to your main issue, the EDB corruption. After making sure the email delivery is working fine with the new empty database you created above, now it’s time to repair the Exchange database file. Start by repairing the EDB with the eseutil tool. However, the native tool will delete corrupt pages of the database, causing data loss. A better alternative to fix the EDB file without losing your emails is to try a professional Exchange Server recovery tool.
Kernel for Exchange Server is designed to repair corrupt Exchange databases while allowing the flexibility to save the recovered data to multiple destinations like PST, Live Exchange, and Office 365. It also offers the facility to migrate shared mailboxes and public folders. It is integrated with a Backup Extractor to restore EDB files from Exchange backup files. The tool is fully compatible with all the latest Outlook and Exchange versions.
The tool allows you to:
- Fix multiple issues within the Exchange Server, including corruption, dirty shutdown, etc.
- Helps restore access to orphaned EDB files by directly converting EDB to PST.
- Allows users to recover all mailboxes together or perform batch restoration.
- Supports large-size EDB file recovery.
- Recover mailbox items without any change to their metadata.
Conclusion
If, due to any reason, the Exchange Server breakdown, the resulting downtime will have severe repercussions on the business. This is because it can take many hours to come back online. To avoid this situation, use Exchange dial tone recovery, which is an advantageous recovery technique.
However, you cannot depend on temporary mailboxes for long. An immediate solution to EDB corruption is required so you can mount the original EDB file back to the Exchange Server. Use our Exchange database recovery tool to repair EDB files, irrespective of the damage.
Frequently Asked Questions
Ans. Yes. All your emails and mailbox data are completely safe. After the recovery, the data from the old EDB and the temporarily mounted EDB will be merged.
Ans. Yes, but I do not recommend it. Instead, it is better if you activate a passive copy of your database. That will be faster and have no downtime issues.
Ans. In normal recovery, the database goes offline, and the email flow stops. While in Exchange dial tone recovery, a new temporary database is mounted to make sure the email communication is not disrupted.
