Wednesday, March 02 2005 @ 08:06 PM EST Contributed by: glosser
The Linux Journal presents this tutorial on synchronizing files between computers.
Keeping directories in sync on multiple machines can be difficult. Running Unison is one way to make the task easier.
Unison is a file-synchronization tool that runs on Linux, UNIX and Microsoft Windows. Those of you who've used IBM Lotus Notes or Intellisync Mobile Suite probably have an idea of what synchronization is good for, as compared to one-way mirroring options such as rsync. You might have mirrored a company document directory to your laptop, for example, and then modified a document or two. Other people might have modified other documents in the same directory by the time you get back. With rsync, you'd need to reconcile the differences between the two directories manually or risk overwriting someone's changes. Unison can sort out what has changed where, propagate the changed files and even merge different changes to the same file if you tell it how.
Think of Unison as two-way rsync with a bit of revision control mixed in. The most common use is keeping your local and remote home directory, or some data directory you often use in different contexts, in sync. It uses the rsync algorithm to keep network traffic down and should be tunneled through SSH over untrusted networks. No extra work is needed-simply specify ssh:// when adding a directory location. Quite a bit of extra disk space often is needed for Unison, though, because the synchronizer needs to keep track of what the files looked like on the last run.
