To be truly effective, a backup application must let you easily choose what you back up, simplify recovery and not slow down your work. So I was looking forward to evaluating DataSentinel, a combination of hardware, software and storage service.
The hardware — a 512MB thumb drive — comes preloaded with the backup software. The software loads automatically (and prompts you for a password) when you insert the thumb drive in any USB slot. The files you select are stored on DataSentinel's servers, for which you pay a fee, beginning at US$5 a month for the first 5GB.
The idea behind DataSentinel is a good one. On the plus side, installation is simple. You insert the thumb drive in a USB port and the program asks you to verify your user ID and password. During installation, your password generates a 136-character "Personal Encryption Code" that you must keep safe. Should you lose your thumb drive, the code is required to recover your data, though the hard copy's black characters against a green background didn't produce a clear printout on my HP LaserJet monochrome printer.
After you've installed the drive, the next step is to select the folders and/or files you want stored on DataSentinel's servers by checking boxes in a tree view. You can also check boxes to exclude files of a particular type (for example, audio files such as MP3 and WAV files), but you have no control over the file extensions for each type. You can also exclude files larger than a user-specified size.
Going to work
Once you've made your file/folder selections (which you can change at any time), the program goes to work, backing up your files in the background. This is where it's clear how DataSentinel differs from other backup options — when it works, that is. To prevent your system from grinding to a halt (a problem with most backup software), DataSentinel backs up at approximately 1MB to 5MB per minute, a speed that's slow enough not to interfere with foreground operations.
When I ran DataSentinel, backups ran at 3MB to 4 MB per minute — a speed that varied depending on the ISP used. A progress screen shows the status of the backup, but I found that if I'd selected a large number of files, it often closed before it could calculate the percent complete. At other times, it reported the backup was 157% complete.
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 75Kb Word file frequently to a folder on my hard drive I'd marked for automatic backup. Each time I saved the file, DataSentinel recognised the update within three seconds and backed it up in less than two seconds, so I was never more than five 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 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. 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.
To restore a file to your hard drive, you're supposed to double-click the file to open it in the associated application, then save the file to your hard drive. That's a simple procedure, but it's limited to data files that are associated with a program. For other files (configuration files or drivers, for example), there's no documented procedure, though I found that selecting the files, copying them and pasting them to my hard drive worked. Unfortunately, there's no drag-and-drop support to easily restore files — a major drawback.
One feature I particularly like is the ability to plug the DataSentinel thumb drive into any PC and back up files for that system. With this feature you can backup a file from one computer and restore it to another.
Quirks and caveats
While day-to-day backup performance of files in selected folders worked well, it's not a program with an interface I quickly understood. Clicking on an icon on an elephant to select files wasn't immediately intuitive, for example, and the "Synchronisation" screen that tells you how far along DataSentinel has progressed often closed before it had calculated the percent complete, and there was no way to "pause" the application so the window didn't close. Furthermore, even after de-selecting all files and subfolders in a folder (so nothing from the folder would be copied to the DataSentinel server), the program insisted on marking the folder as one containing files to be backed up — which was simply wrong. It took several hours until I felt comfortable with how the program worked, but then I kept running into problems. The main window was sometimes slow to respond to mouse clicks or file selections. The program froze more than once and on more than one test machine, adding to my frustration.
When you open a file on the server directly (by double-clicking on it) and save it from an application, DataSentinel automatically assigns a version number to the file and keeps 10 versions of the file; you can't turn versioning off nor set the number of versions you want to keep, so directly editing large files can quickly grow your storage allotment. No versioning is provided for files automatically backed up from your hard drive.
The program had some other, albeit minor, quirks. For example, to end the program completely you must pull out the thumb drive — there's no "File/Exit" command.
Perhaps future users will have an easier time once the company's promised documentation is complete, its performance improves and backup of large files can be relied on. Until then, I cannot recommend this hardware/software/service combo.