Worth to upgrade OS3 to OS5?


I have read quite a lot about suggestions not to upgrade from OS3 to OS5 on Mycloud ex2ultra. Is this still the case? I presume time moves on, old OS leaves more behind and newer OS5 gets better, maybe its wiser to upgrade by now? As a rather newbie on networking and NAS I havent fully understand the downsides of upgrading to OS5.

What I expect the most from my NAS is to store a large volume of music (MP3), photos (JPG) and videos (Gopro MP4) and that they could be EASILY accessed by mobile over cloud. They should be also easily and quickly accessible for viewing, sorting etc from laptop mapped drive under windows explorer. Mobile app for OS3 havent been exactly the handiest I would say, auto upload of photos from mobile to NAS was rather sketchy, it uploaded photos randomly and occasionally, so it was hard to understand how much was uploaded and why wasnt the rest uploaded etc, so I turned it off. Any experience on OS5 being better for mobile access like they say to be ?

Considering my expectations for NAS, would You recommend to upgrade or not?


This is not a simple question.

First. . . .I would not assume OS5 is getting better over time. The feature set has not expanded since first release. . .and nobody is talking about performance improvements. So assume there are none. Indexing in fall of last year was an abomination. . .with the EX2 being the “best” in terms of out-of-the-box performance. . .but still hideous.

Second. . .The advantage of the OS5 mobile app over the OS3 mobile is that it (I believe) works more reliably. In terms of features. . . .there are less features. . .(like . . .copy is missing) . . .and these are NOT being addressed.

Third. . . OS/3 is obsolete from a Security Perspective. OS/5 is “newer”; based upon a more recent Debian build; but let’s not kid ourselves: OS/5 is not the “gold standard” of CyberSecurity excellence. . . and over time. . it will only be weaker.

Finally. . . . OS/5 has raised a number of privacy issues. . .which have not really been addressed.

Overall. . . .

  • OS/5 has some base OS improvements over OS/3 (bug fixes)
  • OS/5 app is more reliable, but has less features than the OS/3 app
  • OS/5 is more secure than OS/3 (which is a low bar, considering how old OS/3 is; and the lack of updates)
  • OS/5 has some user privacy concerns.

For me. . .the user privacy and indexing issues has convinced me to roll back from OS/5 to OS/3 on one unit. The OS/3 units I have are OFF the internet; behind a router that has no internet access. I don’t think WD has a good internet capable product at the moment.


Well, you have very little choice now that WD are cutting off web/remote access to all OS3 devices in April 2022.

So you have a choice of Two OS, neither of which work for remote access (indexing/previews?)


Now that they are cutting off remote access it’s time to switch to Synology NAS. I just can’t believe WD took a capable home office NAS and removed a lot of very useful features. I’ve given up on all 4 of my WD NAS drives! I don’t know who their customers are but it certainly isn’t the home office user.


There are security holes in OS3. It looks to me like OS5 is a rewrite that tries to fix them. I think WD got burned with the My Book Live hack and they do not want a repeat. If you stay on OS3 make sure your device can not be accessed from the internet.

I think the biggest issue with OS5 is the indexing required for their remote access solution. If you do not intend to access your device remotely using WD apps you would be well advised to disable cloud access.

OS/5 predates the big MyBookLive hack by about a year.
Of course, the flaws in that product were probably well known.

Besides the indexing problem, there is a fundamental shift in OS/5 in that it is far more “net aware” than OS/3. Merely turning off webaccess doesn’t keep the unit fully quiet.