Replacement with WD Red Pro?

Hello everyone,

We own a My Cloud EX2 Ultra 2x8TB.
Recently, the disk #1 had SMART failure. The NAS is less than 2-y old…

After checking, the included hard drive are RED « standard » (5400rpm, SMR).

I decided to go for a WD RED Pro 8TB to change the SMART failing drive, especially for the 5-y warranty. The compatibility was confirmed via the support chat, but mail support says otherwise and stick to knowledge base articles (case #221002-000863).

Indeed, the knowledge base articles sound misleading or incoherent to say the least.

First, it reads that 4K drive are not to be used with (any) My Cloud, however all RED drives are said to be advanced format.

In addition, when looking at the list of drives compatibility with My Cloud EX2 Ultra, WD RED Pro are said to be compatible but only starting at 16TB size… despite WD RED Plus (7200rpm, CMR) are said to be OK.

Do you have any thoughts?



Its compatible but you should have got the Red Plus drive.

Wasn’t the original drive still under warranty?

No… Shorter warranty because of RMA…

Why should I have got the Red plus instead?


Because it the same drive as you replaced (specs, performance). The Red Pros are quite a bit noisier, too.

It was a RED “standard” (SMR) (nor Plus nor Pro).

I went for the Pro for the 5-y warranty.

Hopefully, it will work and will not be too noisy.


If it was 8TB, it should have been the CMR (a “Plus” - even if it wasn’t labelled as such). SMR was only supposed to be on 2-6TB.

Well… both hard drives had model number WD80EFAX which relates to Red “standard” to my understanding.


Both of your original Red drives were CMR. EFAX on 8TB and larger are CMR:

On WD Red NAS Drives - Western Digital Corporate Blog.

Understood. Thanks. I did not find this blog post when reviewing all WD docs I was able to find… They don’t have the best KB and search engine there.
Hopefully it will be all OK with the pro.