How to Mount and Dismount Exchange Database: A Complete Admin Guide!

Approved By Ashwani Tiwari

Published On January 22nd, 2025

Reading Time 9 Minutes Reading

Category Exchange Server

Managing an Exchange Server involves numerous tasks, and one of the most critical responsibilities for Exchange administrators is ensuring that databases are properly mounted or dismounted (whenever needed). Mounting and dismounting Exchange database are essential operations for maintaining a smooth-running mail system, performing maintenance, and recovering from failures. In this guide, you will learn about how to mount and dismount Exchange Database, and troubleshooting tips for common issues.

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What is the Dismount / Mount Exchange Database?

Here is a quick overview of both mount and dismount to understand these clearly and simply:

#Dismount an Exchange Database

Dismounting needs to be performed due to various reasons like maintenance, backup operations, migrating data between servers, or when troubleshooting issues. This process makes a database inaccessible to users that could be in an inconsistent or corrupt state. Since it is safe, and nothing can be changed throughout the procedure.

#Mount Exchange database

Mounting Exchange database means making a database accessible for all users in an Exchange Server. When you mount a database, you enable users to access their emails, calendars, and other data stored within the database. Without mounting, the database is not active and cannot be accessible by anyone.

Common Reasons to Mount and Dismount Exchange Database

Mounting and dismounting Exchange database both are crucial tasks for Exchange Admins and for various reasons, we have to perform these tasks:

Database Recovery After Corruption or Failure

Due to hardware failure or any other reason, if you find your database is corrupted, then your first task would be dcamismount the database to make it inaccessible for users and address the issue quickly. When you ensure every error is resolved, you will mount the Exchange database to make it accessible.

Performing Maintenance or Repairs

For weekly checkups or performance issues, the Admin needs to dismount the DB first. After checking the health of the DB, and fixing performance issues mount it again so users can access it.

Migration and Server Upgrades

When need to move data from the older version to a newer one e.g., migrate Exchange 2013 to 2016, or 2019, the Admin needs to dismount the database from the current version, and then mount it to the newer version.

Backup and Restore Operations

Backing up data is a crucial task, in which mounting and dismounting Exchange database plays a vital role. First, you have to dismount it to ensure a clean backup, and then mount it again to resume user access.

Preventing User Access During Critical Updates or Changes

During the Exchange server upgrade, it is mandatory to dismount the database to ensure no interruptions. Afterward, mount the database, and tell users to give feedback about the update because if any issue occurs, then there is a need to dismount DB again to fix it.

Step-by-Step Guide to Mount and Dismount Exchange Database

Mount and Dismount Exchange Database

Mount Exchange Database

Exchange Server provides several ways to mount and dismount databases, and here we will discuss all those i.e. Exchange Admin Center (EAC), EMS, Command Line, and EMC according to Exchange versions.

Before starting with the procedure, ensure that the database is healthy by running this command eseutil /mh “<DatabaseName>.edb” because corrupt data can’t be mounted or dismounted. Additionally, if the database is severely corrupt and standard repair methods fail, tools like the SoftwarePro Exchange Recovery Tool become invaluable. This solution can quickly repair highly corrupted databases and recover data from dismounted or inaccessible databases.

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#Method 1). Use the Exchange Admin Center (EAC) for Exchange 2013, 2016, and 2019

The Exchange Admin Center (EAC) is a web-based management console, that helps to manage Microsoft Exchange Server easily. Additionally, with this, we can mount and dismount Exchange Database by following these steps –

Steps to Mount:

Open the Exchange Admin Center by opening https://<ExchangeServer>/ECP in a web browser.
Click Servers, then select Databases.

Click Servers

From the list of databases, choose DB for mount.
If the database is dismounted, you will see an option to Mount it. Click Mount.

Click Mount

Steps to Dismount:

Open the Exchange Admin Center.
Navigate to Servers > Databases.

Navigate to Servers

Select the database to dismount.
If the database is mounted, you will see an option to Dismount it. Click Dismount.

Click Dismount

#Method 2).Using PowerShell (EMS) for Exchange 2007, 2010 2013, 2016 & 2019

PowerShell commands make it automated & feasible to mount and dismount Exchange Database, but this approach is quite complex and technical to understand. So, it is suggested to run the commands carefully –

Steps to mount exchange database PowerShell:

Open the Exchange Management Shell and verify the correct database for mounting by running this command.

Get-MailboxDatabase

Now, for mounting run this –

Mount-Database –Identity <databasename e.g., > –Confirm:$False

Note – If you find your data is corrupted then repair corrupt Exchange database, use this command for recovery eseutil /r E00 /l “C:\Path to log file” /d “C:\Path to database”. Then use eseutil/mh to verify whether the database is healthy or not.

Steps to Dismount Exchange Database:

To dismount a specific database, use the following command:

DisMount-Database –Identity <databasename> –Confirm:$False

Dismounting several databases simultaneously runs this –

Dismount-Database –server <database name> –Confirm:$False

Add the -Force parameter, if you want to forcefully dismount it, follow the cmdlets:

Dismount-Database -Identity "Mailbox Database 1" -Force

#Method 3). Leverage EMC to Mount and Dismount Exchange Database for 2007 & 2010

Start > All Programs > Microsoft Exchange 2010 > Exchange Management Console.
Go to the mailbox databases > Expand Server Configuration > Click Mailbox.
Find the dismounted database in the middle pane.
Right-click the database and select Mount, or click Mount in the action pane.
Click Yes to confirm the mount.

Steps to Dismount an Exchange Database –

Follow the steps 1 & 2 mentioned above.
Find the mounted database in the middle pane.
Right-click the database and select Dismount.
Click Yes to confirm the dismount.

#Method 4). Using the Command Line for Exchange Version 2003

PowerShell is the advanced option that is used for newer versions to mount and dismount Exchange Database. However, older versions, still need a command line to do so –

Steps to Mount Exchange Database using Command Line:

Run Command Prompt with administrator access.
Go to the Exchange Server’s bin directory, located at C:\Program Files\Microsoft\Exchange Server\V15\bin\.

To mount the DB, run the cmdlets:

eseutil /m <database filename>

Steps to Dismount an Exchange Database using Command Line:

Start Command Prompt as an administrator.
Run the following command to dismount the database:

eseutil /d <database filename>

This is quite a complicated method but not for technical users. However, there is one more solution to mount and dismount Exchange database version 2003:

#Mounting Database:

Within the Exchange System Manager.
Click on Servers > Storage Groups > Databases.
Lastly, right-click the database option > Mount Store.

#Dismounting Database:

For dismounting repeat the same mounting steps, and at last hit Dismount Store.

Best Practices for Mounting and Dismounting Exchange Database!

To avoid disruptions or errors like Exchange not receiving external emails, read and implement this checklist to initiate both the task efficiently:

Always back up databases before dismounting.
Perform mounting operations during off-peak times.
Ensure database replicas are synchronized before mounting or dismounting databases.
Check for corruption using eseutil and IsInteg before mounting databases to avoid data loss.
Review event logs frequently to detect potential issues during operations.
To check if your user account has the required roles, run:

Get-ManagementRoleAssignment -RoleAssignee "username e.g. Joe"

If the Databases role is missing, assign it using:

New-ManagementRoleAssignment -Name "<AssignmentName>" -User "<Username>" -Role "<RoleName>"

After assigning the role, verify it by running:

Get-ManagementRoleAssignment -RoleAssignee "admin"

Reduce Exchange mailbox size to minimize the time of mounting and dismounting Exchange database.

Overall Summary!

Mounting and dismounting Exchange database becomes crucial when managing the Exchange Server. Understanding when and how to mount and dismount Exchange database is critical for Exchange administrators. By using the methods outlined above, Admins can efficiently manage Exchange databases and prevent common issues with the best practices. Remember, corrupted databases won’t be mounted, so first ensure the database is healthy for further processing.

#	Mounting Exchange Database	Dismounting Exchange Database
1	Makes the database accessible to users.	Makes the database inaccessible to users.
2	Enables users to access emails, calendars, and data.	Used for maintenance, backups, or troubleshooting.
3	Users can send/receive emails and access data.	Users cannot access their emails or data.
4	Logs are applied to ensure data consistency.	Logs continue to be written, but no changes are applied to the database.
5	Mount-Database (EMS) or through EAC.	Dismount-Database (EMS) or through EAC.