Drawbacks Of Increased Database Size

An Exchange Database contains multiple user mailboxes and there can be multiple databases in a single Exchange Server. Exchange Server is efficient enough to manage multiple databases. But as the size of the database increases, then the speed of Exchange decreases and creates performance-related issues. Some are described below:

Abrupt database dismount

When the Exchange Server is unable to access information from the database due to its large size, then it dismounts the database which means the connection between the database and the Exchange Server is lost. It is very common for the large-sized database to get dismounted from the Exchange Server.

Slow search

It is difficult to search the mailbox items in a large EDB file of multiple GB size. When you try to search for a unique item, then the search result will bring you multiple items that come under the same search category. It further slows the whole search process.

Corruption in database

A large database is quite vulnerable to corruption and it can affect the items in a bad way. Sometimes, the corruption in the database does not show any error message, but it becomes inaccessible.

Benefits of reducing the Exchange EDB file

When you reduce the EDB file size, it not only makes space for more emails but also brings more benefits to the Exchange Server.

  • The response time of the Exchange Server increases for the mailbox request, and the email communication becomes faster.
  • The white space in the EDB file is reduced and provides more usable space to the email and other information.
  • The older data moves to a different folder and makes the mailbox more manageable.
  • The older data moves to a different folder and makes the mailbox more manageable.
The best practices for Exchange Server Administrators

If the administrators follow the below practices, then he/she can avoid many EDB file issues easily.

  1. Execute Exchange Best Practice Analyzer - Microsoft provides an application called Exchange Best Practices Analyzer that the administrator must use to get an overall picture of the Exchange Server condition and configuration. The tool will retrieve the information related to the Active Directory, registry settings, performance metrics, etc. The administrator will get a clear picture of how Exchange Server is using its resource and regarding the steps to be taken to optimize the environment.
  2. Review the SMTP logs and queues - The SMTP logs and queues contain the information related to the communications through the Exchange Server. If the administrator checks these logs and queues, then it can clear many aspects related to the causes behind message failures. When the messages are stuck in the queues and not processing, then these logs and queues can help the administrator.
  3. Check anti-virus and anti-malware software updates - There is professional anti-virus and anti-malware software that supports the Exchange Server and protects its environment. Sometimes, this software requires the manual update, and the administrators do not run on time; then the software may not provide more security to the Exchange Server. If the administrator updates the anti-virus regularly, then it can help the Exchange perform better.
Three easy ways to reduce Exchange database size

Exchange administrators, sometimes, may not realize the growth of their Exchange databases. And this unusual growth often leads to mounting as well as inaccessibility issues. Luckily, there are many ways to reduce the size of database. Some are discussed here:

Delete unwanted data from the database

It is one of the most obvious methods to reduce the EDB file size effectively. Deleting unwanted data will create free space for adding new data. But make sure you don’t end up erasing important data accidentally. And surprisingly, even after deletion, you may not see any reduction in the size of the EDB file. But don’t worry—the space freed by deleting the data is there and Exchange will use it for adding new data (instead of increasing the databases size).

Perform offline defragmentation or move data to a new database

Offline defragmentation helps to reclaim the free space available (known as white space) in the Exchange database. This process compresses database, eradicates the blank and unused space, and reduces the database size. Thus, it effectively brings continuity in storage. And Eseutil is the Microsoft utility that helps in defragmentation. However, this process has the disadvantage that it is a slow process and can be performed only after dismounting the database (it means that all the mailboxes of the database will be unavailable for a considerable period of time).

Performing defragmentation using Eseutil

You can get the amount of whitespace in a database by running the following cmdlets in Exchange Management Shell:

Get-MailboxDatabase -Status | Format-List Name, DatabaseSize, AvailableNewMailboxSpace –Auto

Before starting defragmentation, ensure that you have enough free space (110% of the size of the database) available on the server (or the network). Now stop the Exchange Information Store service, and follow the procedure below to perform the defragmentation:

  1. In the Exchange Management Shell, navigate to the location of the database file.
  2. Dismount the Exchange database for which the defragmentation is to be done:

    Dismount –Database <Database Name>

  3. Perform defragmentation by running:

    Eseutil /d "<database location\DatabaseName.edb>" /t "<a temporary location\TempDatabaseName.edb>"

  4. Mount the database again

    Mount –Database <Database Name>

  5. After the completion of the defrgamentation process, start the Information Store service.
  6. Check if the database has been mounted, and then verify if the emailing is working.
  7. Finally, check the white space to verify the success of the defragmentation.

Remember: The speed of Eseutil utility usually is 9 GB/hour and may vary according to the hardware and system environment.

Instead of performing defragmentation, many Exchange administrators create a new database and then move mailboxes from the older one to the new one (the older one can be deleted thereafter). It helps them achieve the same results as by the defragmentation. The advantage is that the mailbox down time is negligible. Also, it can be done from the Exchange interface (like Exchange Management Console).

Back up the data and delete it from the server

Exchange administrators can back up the unused data in a different location and delete the same from the server to reduce the database size. For backup purposes, they can use the Windows Server Backup facility. And for exporting, they can try ExMerge or export cmdlets depending on the version of Exchange.

In Exchange 2010, use the following cmdlets to export mailboxes to a PST file:

New-MailboxExportRequest -Mailbox <Mailbox Name> -FilePath < network share path of PST file >

Alternately, they can back up EDB files by exporting data to PST files using an efficient third-party tool like Kernel for Exchange Server. This Exchange Server Recovery tool will make the entire process effortless offering many flexible options.

Save to PST


To reduce Exchange database size, you have many options—delete unwanted data, perform defragmentation, move data to a new database, delete unused data after creating a backup, etc. And for backup purposes, you can try Windows backup utility, use inbuilt export utilities, or convert EDB to PST file using a third-party tool.