Performing an Offline Defragmentation of Exchange

by Chris Sanders [Published on 20 Feb. 2008 / Last Updated on 20 Feb. 2008]

One of the best ways to increase the performance of an Exchange Server is to perform an offline defragmentation. Here is how to do it.

One of the best ways to increase the performance of an Exchange Server is to perform an offline defragmentation of it. As an Exchange Server spends more and more time in production its data store gets just as fragmented as a typical computer would during use. This means the Exchange database is full of information that it may not necessarily need.

In order to perform an offline defragmentation you will first need to take the server offline so that it is inaccessible by users. You can do this from System Manager, right clicking the information store in use, and clicking Dismount.

After doing this, open a command prompt window and browse to the bin folder in the Exchange Server installation directory. Begin the defragmentation by typing the following:

esutil /d c:\location\of\mdbdata\priv1.edb

It is important to note that this process could take quite some time so you should probably do it after hours as opposed to a peak usage time so that your users aren’t too ticked off at you. You will also want to note that the amount of free disk space on the server should equal at least 110% of the exchange database size or else there will not be enough space to complete the defrag. Lastly, you will, as always, want to make sure that you have a full backup of the server before completing this process.


Chris Sanders is a consultant for KeeFORCE, one of the most popular network consulting firms in western Kentucky. Chris is the author of the book Practical Packet Analysis as well as several technical articles. His personal website at contains a great deal of information, articles, and guides related to network administration, network security, packet analysis, and general information technology.

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