Performing defragmentation in EDB files makes the used storage closest, minimizes unused storage and compacts the database that ultimately reduces the size of the database. Eseutil copies database records to a new database. When defragmentation process completes, the original database is deleted or saved at a desired location, and the new version is renamed as the original. You can use Eseutil to defrag the EDB database, by following the steps given below:
Step 1. In Exchange System Manager, right-click the Information store that you wish to defragment and then click the Dismount Store option
Step 2.In the command prompt, change to Exchsrvr\Bin folder and then type the eseutil /d command, a database switch and any options that you want to use
However, if the eseutil encounters a bad record, it stops and displays an error message. At this point in time EDB recovery must be performed; else, you might just lose all your important data. EDB recovery can be performed flawlessly with Kernel for Exchange Server repair tool.
Note- While defragmenting a database; make sure that you will require free disk space of 110 percent of the size of the database.