Bigsync is a free and open source command line based tool to incrementally backup a big file to a slow destination (think network media or a cheap NAS).
The most common cases for bigsync are disk images or virtual OSes or encrypted volumes.
Bigsync will read the source file in chunks calculating checksums for each one. It will compare them with previously stored values for the destination file and overwrite changed chunks if checksums differ.
This way we minimize the access to a slow target media which is the whole point of bigsync.
· bigsync --source /home/egor/Documents.dmg --dest /media/backup/documents.dmg.backup
· bigsync --source /home/egor/Win.vdi --dest /media/backup/virtualmachines/
Bigsync vs rsync
rsync does kind of the same thing, too. But rsync does read both files to calculate checksums, which slows down the whole process a lot when working with slow media. Bigsync only reads source file, and writes only changed blocks to destination, which minimizes load and access to the destination drive.
Installation: Unarchive, open a Terminal window, go to Bigsync's folder and run the following commands from the command line (afterwards run the program using its name "./bigsync"):
· Apple Xcode (to build Bigsync from source)
What's New in This Release: [ read full changelog ]
· Fixed destination path bug.