Replace existing files only (do not add files)

If this option is checked, when SureSync runs a synchronization it will only synchronize a file if it already exists. No new files will be added. This allows files to be distributed without adding files that are not needed or used.

Copy only to existing destination folders

If this option is checked, SureSync will only synchronize files in a subfolder if that subfolder already exists on the destination. If the subfolder does not already exist then it and its contents will be skipped. With this option on SureSync will not add any new folders.

Delete destination files before copying

If you check the 'Delete destination files before copying' option and specify a file size then SureSync will delete large files from the destination before copying the updated copy. This is useful for computers with low spare disk space. For safety reasons SureSync copies files to a temporary file and then renames the temporary file to the actual name when the file transfer is completed.. A side effect of this is that for a short while you have two copies of the same file in one place. If it is a large file this could cause problems with disk space. If you enter a size in the box (it can be in Bytes, KB, MB or GB) any file larger than that cutoff will be deleted before it is copied so you will only have one copy of the file on your drive at any one time. You can type in a size manually or use the arrows to scroll the size up or down.

Copy Alternate Data Streams

This option is selected by default. Checking the 'Copy Alternate Data Streams' option tells SureSync to copy alternate data streams when copying files. Removing the checkbox for this option tells SureSync to copy the files but not the alternate data streams.

An alternate data stream is a part of the NTFS file system. There are many different types of alternate data streams. These streams can be user created or program created. For example, Microsoft Word uses an alternate data stream to store the information found on the 'Summary' tab of a Word file. In general, it is a recommended that you always copy alternate data streams.

If you synchronize data to a machine running drives formatted as a non-NTFS file system, you will receive errors about the files not being copied because alternate data streams are not supported. This is common when synchronizing to non-Windows NAS boxes or to things like USB thumb drives. It is still recommended this option be selected and that the 'Copy files with alternate data streams even if streams are not supported' option be selected on the Options tab of the Relation. This will allow SureSync to copy the alternate data streams to devices which support them and drop them when copying to devices which do not.

Copy Reparse Points instead of the file contents referenced

By default, when SureSync encounters a reparse point, it will synchronize the folders and files that the Reparse Point points to. In other words, the destination will contain copies of the actual files, not the Reparse Point.

If you check the 'Copy Reparse Points instead of the file contents referenced' checkbox, SureSync will copy the Reparse Point to the destination instead. This means the files will not exist on the destination, just a Reparse Point pointing to the files which are stored somewhere else.

If the file size is different but the dates are equal

This set of options allows you to determine how SureSync should handle files which have the same modification dates but different file sizes. This occurs in some applications when a file is opened, but no changes are made. In this instance the modification date does not get altered, but the program stores some data within the file for its own reference, hence the size difference. However, if the user opened the files and compared them they would appear to look exactly alike. You can have SureSync log an error and not copy the file, ignore the size and treat the files as if they were the same, copy the larger file over the smaller one, or copy the smaller one over the larger one. This option is only displayed if you are working with a multi-directional Rule. If your Rule is one way, the source will always copy over the receiving end when the files are different.