I have about 30 thousand photos taking up about 65 Gigs of disk space. I keep 4 copies of these photos across two external disk, one PC and a laptop. As the amount of data is huge keeping the four backups in sync is a tough job and manual copying is impractical. For a brief time I used a software called Areca for backup and it worked perfectly fine. In fact I used Areca till I came across rsync.net backup agent from rsync.net.
Rsync.backup agent was much faster than the version of Areca I was using. It so easy to set up and in 30 minutes I was using a profile the exact way I wanted. I was so amazed by the capabilities of this software and it looked like this piece of software was written for me.
The Rsync.net backup agent builds a database with the details of the files of the files to back up and uses this database when the back up is performed. The back up process is very fast. It takes about less than a minute to identify the files that are changed.
To set up back up, the backup profile need to be set up. Switch to wizard mode and select the "Create a new backup profile". The next screes will take you through the necessary steps. In these steps you can select the left hand side folder, right hand side folder and the direction in which the back up has to happen. Once the destination and the direction of sync is selected, the back up mode can be selected. Rsync.net provides 3 types of backup operations namely "Standard copying", "Smart Tracking" and "Exact Mirror". The smart tracking option provides a choice of moving the deleted files to a predefined folder. So if a file is deleted by accident, in the back up, the file will be moved to the predefined location. Masks can be used to include or exclude files and folders in the backup. The profile can be set up to be executed automatically at predefined time as well. Profiles need to be saved with a name and if multiple words are given for profile name, first word of the profiles are used to group them.
Another interesting feature is the partial file update. For very large files, Rsync.net backup agent can identify the changed location and copy a subset of the file and keep them in sync between source and destination.
For individual usage the rsync.net backup agent is the perfect choice and they offer a paid on-line backup option as well. Going by my experience with the rsync.net backup agent software, I would imagine that the on-line backup will also be equally good.
I switched to the real rsync a while ago when my primary laptop died due to hardware issues. Needless to say, no data was lost since I had the backups. Now my photos take slightly more than 250 GB disk space.