There's a downside to the slow speed. Depending on how many files and folders you initially select, your first backup may take many, many hours to complete. Furthermore, if you make minor changes to large files (a graphics-rich PowerPoint presentation, for example) and want to shut down your system right away, you won't have time to protect your files. Fortunately, any file not backed up before you turn off your computer will be synched to the server when you next boot up and reinsert the DataSentinel device (From insertion of the thumb drive until the software opens the file view is about 90 seconds.)
Once the initial files I selected were backed up, DataSentinel's performance varied. For example, as I worked on this review, I saved the 75K Word file frequently to a folder on my hard drive I'd marked for automatic backup. Each time I saved the file, DataSentinel recognized the update within 3 seconds and backed it up in less than 2 seconds, so I was never more than 5 seconds away from a backup copy on the DataSentinel server. That's peace of mind. DataSentinel took roughly 15 seconds to spring into action when I saved a new file to the same folder for the first time. Unfortunately, a 300MB video file never was successfully backed up. The file remained on my hard drive, of course; it was never completely backed up to the service. The 10MB that did make it through the Ethernet and to their servers remained on the service, and the file list shows a file size of 10MB for the file -- but unless you know this is a 300MB file, I wouldn't have known that the file was incomplete on their server. In other cases, when the individual file hadn't been backed up at all , the "size" column remained at 0, which is logical.
If you need to save a file immediately, DataSentinel provides a "Private" folder. Drag a file to this folder and the file is copied as quickly as possible -- sometimes. This option worked fine when saving several 6MB audio files, but a 350MB video file never made it to the Private folder, and the status bar inexplicably disappeared after just 3% of the job was complete. I had to stop and restart the backup service so DataSentinel could "wake up" and do a bit more of the backup each time. I gave up after repeating that process 10 times, with the file transfer still incomplete.
Awkward data recovery
If you delete a file from a folder on your hard drive, the file is kept on DataSentinel's server. To permanently delete an archived file from the server, you must click on the Pencil icon in the file list; DataSentinel displays these deleted files with a light-yellow background (see Figure 3). However, I found that right-clicking and choosing the delete command didn't work consistently. For example, I tried to delete an empty folder but was never successful, and using the command often froze the software. Because the service is priced on the number of gigabytes you store, successful deletion is important -- you may want to regularly review what's on the server so you don't pay for storing obsolete files.