How to Restore Exchange Mailboxes Without Overwriting Existing Data Guide

How to Restore Exchange Mailboxes without Overwriting Existing Data

The crucial and confidential nature of organizational data stored in the Exchange mailboxes needs utmost protection from cyber attacks and internal errors. The data may still go missing or become corrupt after adopting all the security measures. This makes it essential to restore the mailbox database to its initial state.

While doing so, do not overwrite the existing mailboxes, as it will lead to permanent data loss. To carry out the mailbox restore, you should have all the required administrator permissions and deep technical knowledge. Let’s find out more on ways to restore Exchange mailboxes while avoiding overwriting existing data.

What is the need to restore deleted Exchange mailboxes?

Exchange Server may lose mailboxes and the contained data for various voluntary or unexpected events. Prominent of these may include:

• Accidental or unintentional administrative deletion
• Malware attack
• Abide by legal compliance
• Employees offboarding
• Exchange database corruption
• Storage or Hardware failure
• Exchange server crash
• Failed mailbox migration

While all these acts result in the loss of mailbox data, its quick retrieval is crucial to ensure smooth business continuity. This eventually creates the need to restore the deleted Exchange mailboxes at the earliest. However, you should take care not to overwrite existing data while restoring Exchange mailboxes, as it will complicate things further.

Why should you avoid overwriting existing mailbox data?

When you try to restore your exchange mailboxes by overwriting existing data, you are taking a big risk of data loss. While recovering a deleted data is still possible if it remains in the disk during the retention period, but overwriting will eliminate your existing data, leaving no chance for recovery. You will have no earlier emails, calendar events, or contacts unless there is a backup. Here are more disadvantages of overwriting with respect to the mailbox data:

• Permanent loss
• Completely Unrecoverable
• No historical remains
• Obstruction in current email routing
• Corrupted permissions
• Complicated Compliance eDiscovery

Which methods do not overwrite existing data to restore Exchange mailboxes?

Data overwriting refers to replacing the old data with the new one at a specific location in your system. This method must be your last resort when you have no other option left. Here are some other common methods used by administrators to restore Exchange mailboxes:

Restore data through Recovery Database (RDB)

A recovery database enables you to mount and extract data from a restored mailbox database during a recovery operation. It recovers the database by using its copy or a healthy backup, without disturbing the users’ access to live data. Using New-MailboxRestoreRequest cmdlet is a suitable way to take out data from the restored database. Next, export the retrieved data to a folder or an existing mailbox.

Things to know before restoring the database using RDB

Have the necessary permissions assigned before starting the procedure.
Copy or restore the database and the associated log files consisting of the recovered data into the RDB folder structure
Change the status of the restored database from a dirty shutdown state to a clean shutdown state using Eseutil /R.

Use RDB for data recovery through Exchange Management shell (EMS)

Here is how you can use the recovery database to recover the Exchange mailboxes through EMS without overwriting the existing data:

1. Restore the corrupt or damaged database and its log files to the target location that you have chosen for the recovery database.

2. Bring the database to a clean shutdown state using the Eseutil /R command.

Eseutil /R EXX /l <RDBLogFilePath> /d <RDBEdbFolder>

Here EXX refers to the prefix for database log generation. Let’s consider an example:

Eseutil /R E01 /l E:\Databases\RDB1 /d E:\Databases\RDB001

E01: log generation prefix

E:\Databases\RDB001: path to the recovery database and log file

3. Next, create a recovery database with a unique name using New-MailboxDatabase along with EdbFilePath and LogFolderPath parameters.

New-MailboxDatabase -Recovery -Name <RDBName> -Server <ServerName> -EdbFilePath <RDBPathandFileName> -LogFolderPath <LogFilePath>

Example:

New-MailboxDatabase -Recovery -Name <RDBName> -Server <ServerName> -EdbFilePath “E:\Databases\RDB1\DB001.EDB” -LogFolderPath “E:\Databases\RDB001”
This command creates a recovery database to recover the database DB001.edb and its log files, located at E:\Databases\RDB001.

4. After creating the RDB, restart the Microsoft Exchange Information Store service by using the command: Restart-Service MSExchangeIS

5. Proceed to mount the database using the command: Mount-database <RDBName>

6. Make sure that database you just mounted consists of the mailboxes you wish to restore by using the Get-MailboxStatistics cmdlet.

Get-MailboxStatistics -Database <RDBName> | Format-Table DisplayName,MailboxGUID -AutoSize

7. Restore the mailbox or its items from the RDB to a target mailbox.

Example 1:

New-MailboxRestoreRequest -SourceDatabase DB001 -SourceStoreMailbox 1d20855f-fd54-4681-98e6-e249f7326ddd -TargetMailbox JohnD

This example restores the source mailbox with the Mailbox GUID 1d20855f-fd54-4681-98e6- e249f7326ddd from mailbox database DB001 to the target mailbox named JohnD

Example 2

New-MaiboxRestoreRequest -SourceDatabase DB001 -SourceStoreMailbox “John Doe” -TargetMailbox johndoe@contoso.com -TargetIsArchive

This example restores the items of the source mailbox John Doe on the mailbox database DB001 to the archive mailbox for johndoe@contoso.com.

8. Use the Get-MailboxRestoreRequest cmdlet to check the status of the mailbox restore request. Once the status shows completed, use Remove-MailboxRestoreRequest to remove the restore.

Get-MailboxRestoreRequest -Status Completed | Remove-MailboxRestoreRequest

Risk with RDB and other Exchange mailbox restore methods

In addition to the RDB method, you may also use several other methods to restore Exchange mailboxes. For instance, you may perform database soft recovery (Eseutil r) or hard recovery (Eseutil /p).

Additionally, there is also the option for Native Exchange Search & eDiscovery. Nevertheless, these methods may accompany several drawbacks. For example:

• In case of RDB, a heavily corrupted live mailbox or database can reject the restore request.
• When using Eseutil commands, soft recovery may trigger errors and a hard recovery would lead to significant data loss.
• During eDiscovery, a malicious script or a ransomware may badly corrupt the data, making it unusable
• All these methods need you to have an in-depth and practical knowledge of the involved operations.
• Often, it becomes hard to prevent data overwriting despite using all the precautionary modes. To avoid these issues, you can try using automated Exchange recovery software.

Restore Exchange mailboxes using Exchange recovery tool

When the manual methods lead to excessive downtime, loss of data, or database mounting errors, it is better to find a suitable third party tool to restore Exchange mailboxes. Stellar Repair for Exchange is a workable alternative to consider in this line. The software can perform multiple functions satisfyingly restore Exchange mailboxes. Some of the crucial functions it performs include:

• Repairs damaged or corrupt EDB files
• Restores and recovers deleted Exchange mailbox items
• Exports restored mailboxes and the contained items to PST, Office 365, or Live Exchange
• Carries out eDiscovery Search &amp; Granular Recovery
• Provides an enhanced preview of mailbox items
• Fixes Exchange database mounting issues and EDB corruption
  All these points make the software a worth considering option to restore Exchange mailboxes.

Conclusion

When restoring Exchange mailboxes, it is better to avoid overwriting the existing data, because it will lead to permanent data loss. Several methods can help to serve this purpose, for instance Recovery Database is a widely used option to restore database to a different target location, to avoid overwriting. Likewise, you may also opt for Native Exchange Search &amp; eDiscovery or Eseutil commands. These manual methods help in executing the restore operations with success but may lead to downtime and mounting errors. Moreover, using hard recovery using Eseutil /p command will also lead to data loss.

To avoid these results, administrators use several Exchange recovery software. Stellar Repair for Exchange is a suitable alternative in this context. It helps to restore Exchange mailboxes with just a few clicks and without requiring you to be familiar with the associated technical jargon and the Exchange mailbox environment.