I already do backups from my main computer to my server computer using synctoy.

But now I also want to do off-site backup.

My idea so far:

• have source hard drive (we'll call S) at home
• have backup hard drive at work called B
• have transport hard drive called T
• connect T at work and record index of files on B
• take T home and check index of S and note new/changed/deleted files and copy changed files to T
• take T to work and update S
• repeat

Its basically a sneakernet and using all of the advantages of it. High bandwidth, low latency.

Is there some software to do this, or do I have to write it myself?