Configuration

Because FreeFileSync is a powerful tool, it has a fairly large set of options to configure. You can set up the general parameters for the tool in the Extras | Options dialog, which you open via the menubar at the top of the screen. You will find all the configuration options that need to be made independently of synchronization tasks here (Figure 2).

Figure 2: FreeFileSync has extensive configuration options due to its rich feature set.

In this dialog, you define, for example, how long logfiles remain in storage, where the software stores them, and whether the application should output audible signals when actions are performed. You can also customize existing context menus in this dialog.

In contrast to these settings, which are generally loaded when the software is called, you will find three further configuration dialogs in the Actions menu. The Compare Settings, Filter Settings, and Synchronize Settings entries let you create profiles that the program loads as a function of the file, directory, and action.

In the first tab, Comparison, use the Comparison Settings dialog to define the criteria that FreeFileSync applies to compare files. You have the choice here between date and size, file content, and file size. In addition, you can specify whether the program should follow symbolic links to locate identical files. The Filter tab (the funnel icon located top center in the dialog) opens an area where you enter the directories to be included and excluded in a list. You can also filter the data here based on file sizes.

The right tab Synchronization offers different ways to synchronize data. This is also where you can define individual criteria for synchronization. Basically, the options depend on whether an object already exists in one of the active directories and how the software should proceed if different versions of a file exist in the source and target directories.

If FreeFileSync detects unresolvable conflicts in object pairs during synchronization, the dialog also offers a configuration option for this. In addition, you can specify in this tab what happens to deleted and overwritten data. You can choose between deleting the data permanently or moving the data to the recycle bin so that you can restore if needed.

Dry Run

After finishing the configuration, start comparing the directory contents. To do this, press the Browse button below the Compare and Synchronize buttons in the program window, respectively, and select the desired directories in the file manager. The application automatically adopts menu hierarchies recursively.

If you want to compare multiple folder pairs with the same compare and sync settings in a single operation, press the small plus button on the left below the large Compare button. The software now adds another input line for a folder pair.

To additionally include cloud storage or a central server on the intranet in the data synchronization, press the button with the cloud icon to the right of Browse. The program now opens an overlapping configuration window that lets you either include your Google Drive online storage in the synchronization or talk to a server via FTP/SFTP. In both cases, the respective target can be configured in a few steps in this dialog so that FreeFileSync accesses the directories available there.

After selecting the directories, press the large Compare button. The software now compares the folders, displaying the files it finds on the left and right in the two large window segments at the bottom. The green arrows with the plus symbols pointing in different directions between the two folder displays show you which files the software is backing up if you compare from left to right and vice versa. The arrow colors show the transfer direction: Arrows in green mean the file is being transferred from left to right, while a blue arrow refers to the opposite transfer direction (Figure 3).

Figure 3: The number of files to be transferred is represented by arrows: green from left to right, and blue in the opposite direction.

Synchronizing

Depending on the profile you created, you can then synchronize the two directories by selecting Synchronize. If necessary, you can modify the existing profile settings before the sync by pressing the small triangle button to the right of the Synchronize button and selecting the desired configuration dialog from the context menu.

In addition, the software lets you customize the sync for each listed file, if needed. There are three alternatives to choose from: Either copy the file (which is usually suggested) in the respective direction specified, delete the file, or ignore it.

In addition, some details of the intended sync are displayed in a small statistics area bottom right in the program window. The stats provide information on the number of files the software copies or updates in each direction and quantify the number of planned deletions as well as the transfer volume. If syncing involves massive copying processes, you can see in advance how much disk space you will need. You can adjust the configuration later by clicking on the funnel icon top center. This opens the filter dialog, where you can include or exclude directories or certain file formats from the sync.

After completing the settings, start the process by pressing the big Synchronize button. FreeFileSync now synchronizes the data based on the defaults and displays the action's progress in an overlapping window. It tells you, almost in real time, the number of files that are still to be synchronized.

Note that in the case of slower removable media that communicate with the computer via USB 2.0, writes may still be taking place even if the software is already indicating a full sync. This is why you need to wait before unmounting the removable disk to make sure that the synchronization is complete, and – if the system is still working with the disk – wait for it to be released.