Bigsync is a tool to incrementally backup a single large file to a slow destination (think network media or a cheap NAS). The most common cases for bigsync are disk images, virtual OSes, encrypted volumes and raw devices.

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's existance.

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

Download source. make. make install.

Supported OS

"Officially" used in and compatible with:

• Mac OS X 10.5 both PPC and Intel in both 32bit and 64bit;
• Mac OS X 10.6 in both 32bit and 64bit;
• Mac OS X 10.7;
• Any Linux in both 32bit and 64bit.

Perhaps bigsync will work on any POSIX-compatible unix except really ancient ones with broken glibc like CentOS 4.

Bugreports/suggestions/patches

Open an issue in this project or mail me at me@egorfine.com. I appreciate it!

History

0.1.0 at Apr 14, 2012 sparse files support, raw devices support, bugfixes, test suite.

0.0.9 at Jan 9, 2012 fixed critical bugs related to support of large files on 32bit systems; also misc fixes.

0.0.8 at Dec 10, 2011 stat64() changed to stat(); truncate() changed to ftruncate(); misc fixes.

0.0.7 at Apr 9, 2011 buffer overflow fixed; better compilation options; misc fixes.

0.0.6 at Apr 13, 2010 verbose and quiet modes added; misc compilation fixes.

0.0.5 at Nov 19, 2009 initial public release.

Note: new versions aren't released very often. The only reason: bigsync is about perfect.

Acknowledgment

Special thanks to Western Digital for producing «MyBook World Edition», which is so incredibly slow that it motivated me to create bigsync.

Thanks to Andrew Suslov for helping me. Thanks Dirk Huffer for sparse files support.