Super Flexible File Synchronizer

Partial File Updating

Partial File Updating is a feature that makes updating of large files faster if only some parts of the files have changed. This could be true especially for large databases such as Outlook .pst files. Partial updating needs to have fast access to at least one of the sides of the synchronization. The other side may be a low-bandwidth connection.

This feature can work in two different modes:

Mode 1: Slow Destination

In this mode, the speed-up is available when you copy files from a location to which you have fast access (preferably your own hard disk). The destination can be a slow connection, but it must be a normal file system (either LAN or VPN) or SSH/SFTP.

Instructions for Mode 1

In your profile, make the following checkmark: Use Partial File Updating, which is on the Specials tab sheet when editing the profile in Advanced Mode. The next time you run the profile, a .syncdb database is created on your hard drive where information needed for the speed-up is stored. The second time you run the profile, you should notice the speed-up.

Only files with a size of at least 400,000 bytes are affected by the speed-up. The file is handled in slices of 200,000 bytes each. An MD5 checksum is used to determine whether a slice has been changed and needs updating. Therefore, there is a minute, totally unrealistic chance that a change might not be detected.

Mode 2: With ExtremeSync Remote Service

This mode can speed up updating large files in both directions. The remote computer can be both source and/or destination. This is achieved by running a small service application on the remote computer, which will create the necessary checksums when requested by the main application running on a different machine. To install the ExtremeSync Remote Service on the remote computer, you need to have administrative access to that system, which has to be running Windows or MacOS.

The other (local) computer, where the main Super Flexible File Synchronizer is running, needs to have normal file system access to the remote computer (LAN or VPN). It needs to have write access to the remote computer so that it can save the checksum request file there. The MD5 checksums are created when needed, so that no database is being used.

Support for an FTP connection will be added in a later release.

Instructions for Mode 2

On the remote system, run the Setup program and install the ExtremeSync Remote Service along with its control panel. Start the control panel from the Super Flexible group in the Start menu.

On the tab sheet Configure Checksummer, enter the base folders that will be used for synchronization. Click Apply.

On the tab sheet Service Configuration, click on Install Service and Start. The service will be using the Windows System account by default. If this account doesn't have sufficient access privileges, you may have to change the account in Windows Control Panel -> Administrative Tools -> Services.

On the local system, you are running the main program, Super Flexible File Synchronizer. In your profile, the right-hand side must be the remote system. Specify one of the folders which you have specified for the remote service to monitor. The left side should be your local folders, or a network drive with relatively fast access. On the Specials tab sheet in Advanced Mode, make the following checkmarks: Use Partial File Updating and Right side uses Remote Service.

That's it! Subsequent file updates should be much faster, if the file already exists on both sides, and if only a portion of the file has changed.