There is a fair amount of misinformation regarding the Western Digital (“WD”) MyBook Duo series with respect to encryption and potential data loss. I am sharing my experiences.

1) Software encryption: this is enabled by the user by adding password protection via the included WD software. It can be enabled or disabled by the user (assuming you have the correct password).

2) Hardware encryption: there is none. However, the RAID is implemented via hardware in the MyBook Duo enclosure. The implications of this design are as follows:
a. The proprietary nature of the hardware RAID implementation means that the individual disk drives CANNOT be read outside of the MyBook Duo enclosure. I believe this is not unique to the MyBook Duo as many other RAID enclosures have the same characteristics.
b. The RAID implementation is the same from enclosure to enclosure. Therefore, a drive created in one MyBook Duo enclosure CAN be installed into another MyBook Duo enclosure and READ SUCCESSFULLY. (As I have two MyBook Duo’s, I have physically tested this.)
c. If the MyBook Duo enclosure fails for any reason, a replacement enclosure will read the disks successfully. The data IS NOT LOST.

3) With respect to temperature, when running continuously for an hour or more (such as when performing a backup), the drives reach temperatures in excess of 55C. While I believe the drives can endure such temperatures, I believe that is hotter than desired. Therefore, I recommend that Western Digital updates its design of the MyBook Duo enclosure to include a small exhaust fan.

4) I have added small, 80 mm (3”) USB-powered variable-speed fans that sit directly on top of the MyBook Duo enclosures to help expel the excess heat from the drives. Even though the fans are small and virtually silent, they are probably overkill as it only takes a minimal amount of extra air movement (the fans are at the lowest setting) to keep the drives comfortably below 40C, even when running continuously.

5) Overall, I am happy with the MyBook Duo (8TB drives). While I do believe the lack of a fan is a non-optimal design decision, it is easy to add an exterior fan that works very effectively at maintaining more desirable drive temperatures.

Purchased this external hard drive to expand storage capabilities on an Xbox One. Plugged the drive in to one of the three Xbox USB 3.0 ports, followed the prompt to format the drive to store game data, and was ready to go. It was easy to move existing game data from the internal drive to the external drive. Note: You will need space on your power strip or electrical outlet to plug in the power adapter.

If you are using this drive with the Xbox One and use a lot of accessories that also need USB ports, you may want to buy a 4-port USB hub. I wasn't thinking about that when I bought this and had to pick one up later.

Inside is WD80EZZX. 5400rpm Helium drive. From my performance benchmarks it looks like a PMR drive rather than SMR one (e.g. Seagate).

Very impressed with enclosure and the ease of setting it up. It is quiet with very fast transfer rates (not formally tested, but moved whole movies within seconds). Easy to service and replace drives. I am pleased that it uses the server-grade Red drives as this should improve reliability. Absolutely love the two additional USB drives on back which essentially serves as an additional USB 3.0 hub. All modes (RAID 0, RAID 1, JBOD) tested and work well. FYI, JBOD (just a bunch of disks) offers access to two drives which can be formatted in your choice of filesystems (FAT32, NTFS, ReFS, etc). IMPORTANT NOTE: Out of the box, the drive is RAID 0 mode and requires additional steps to change into a different mode (highly recommended).

When looking into a backup or storage solution, one should consider all potential points of failure. Perhaps more importantly, one should have a recovery plan for each of the failure scenarios. I have attempted to list all these possible points of failure. In order of descending likelihood (your order may differ):

1. Single drive failure (not a question of if... but when)
2. Enclosure failure (internal RAID controller malfunctions, power supply failure, etc)
3. Catastrophic failure (theft, fire, simultaneous complete failure of BOTH drives)

Firstly, for castrophic failures there are no recovery options. This is why critical information should always be backed up OFF-SITE, and why RAID is generally not considered a viable option for backup purposes.

The most common form of failure is the single drive failure mentioned above. Importantly, RAID 0 will NOT protect against this common type of failure. Expect complete data loss! Thankfully, the RAID1 setting will help protect against the fairly common problem of single drive failure. Therefore, if you do not NEED the maximum capacity, I would highly recommend the RAID1 (data-mirroring) setting. In this case, even if one drive malfunctions you will have access to all your files. To successfully repair the mirroring function will require identification of the malfunctioning drive (which can sometimes be tricky) and then replacement with a new/different hard drive. In RAID 1 mode, the new disk will be re-populated with all the files from the working disk (hence the term mirror) and once again your files are protected from a single disk failure.

One frequently omitted consideration is what would happen if the enclosure/RAID controller failed. In this scenario, there would be two functional but inaccessible disks "trapped" inside the enclosure with no access to your files. Though I did not test formally on this drive, in many RAID1 setups you should NOT expect to be able to take out the drives and simply connect them to your computer to get to your files. Often times there is hidden formatting on these disks that prevents them from being natively recognized by Windows and MAC. While I was not able to find any documentation on this specific drive, I did find complaints from WD My Book LIVE Duo users who had difficulty recovering files. Many of those users described having to pay for expensive recovery service or needed to access the disks using a Linux system.

With that concern in mind, as a Windows 8+ user I setup my disks in JBOD mode which allowed me to use a new feature in Windows 8 called Storage Spaces. Storage Spaces works as a form of "software RAID" that also mirrors your data across two or more disks. One potential advantage of this setup is that an enclosure failure would be a comparatively minor inconvenience. I was able to find documentation that stated that access to your files could be maintained by hooking up either of the drives directly to your personal computer (without the enclosure). As such, a potentially costly and timely recovery process might be avoided. Also Storage Spaces allows for a mixed RAID setup using the two disks in the My Book DUO. For example once the two disks are added to the storage pool, I can make two different "drives" using this setup: (1) A mirrored disk which has built in redundancy, and (2) a striped disk with improved performance and the ability to use more of the available disk space. In my setup using a 6TB My Duo Book: Drive (1) is a mirrored backup drive with 1.5 TB of files on it (uses 3TB on the drive because it is mirrored), while Drive (2) being a "scratch" drive with a total of 3TB of free space. Using a setup like this, one can achieve backup of important files while maximizing storage space: 1.5 TB + 3 TB = 4.5 TB as compared to 3 TB on a fully mirrored drive. FYI, a drive that is setup using Storage Spaces is not compatible with Windows XP, Windows 7, or any other operating system (MacOS, Linux, etc).

As stated above, I researched but did NOT personally test any of these failure scenarios. If you have personal experience with recovery of files from this drive, feel free to update in the comments sections. Good luck to you and your precious data. Enjoy.