Does Drobo 5c support 16TB HDD? (of course CMR)

Hi, I am using 5c and already installed 4 of WD Gold 12TB HDD and 1 of WD Gold 10TB HDD. Of course CMR type only. Can I replace one of those to WD Gold 16TB HDD?

I have checked the supported HDD list for 5c but listed drives are up to 14TB.


The largest drive Drobo have tested is listed as 14TB.
Maximum Volume Size and Largest Size Drive (

Some have reported 16 or 18 TB drives as working, Personally I’d be wary of going too big as I’m unsure what happens if you exceed the listed Max Storage.

I actually asked this question to Drobo support last year, while my Drobo 5N2 was still in support.

This was my support ticket:
“The support pages for my Drobo 5N2 lists that the largest drive size tested is 14tb:
In a community post, it seems Drobo support has indicated that 16tb drives were now supported:

Would this same logic apply to 18tb drives (or larger)?”

The response from Drobo support:

“Yes, for the most part.
We have not tested drives that large, they will very likely work.
Just keep in mind the models we do not recommend - Can I really use any hard drive I want in Drobo?
​Make sure any drive you buy for a Drobo does not use SMR technology for storage. Any drive using that is not compatible.
You are also still limited to the 64TB volume size.
So, if you were to fill a unit with 18TB drives you would be over that volume limits and that extra space would be unusable anyway.
5 x 16TB drives in a 5N2 would put you at exactly 64TB usable space (4x16 because 1 drive is the redundancy drive)”

Since your 5C has similar specs to my 5N2 (minus the NAS part), I would assume this response also applies to your case. I have 2 x 16TB drives in my 5N2 since last October, and I’ve had no issues.



Sirs, many thanks for comments.

I also found a KB article on product page (JP site), it says the total size of installed HDD size must be equals or less than 64TB but no specific upper limit of individual HDD size (but the supported HDD list is up to 14TB).
So, I decided to try using a HDD of 16TB from WD Gold HDD series.
The total size will be 12TB * 4 + 16TB = 64TB.
I will get back as soon as I check it out with result.


As per the comment from @dom1, a combined HDD array with a physical capacity of 64TB will not result in a fully maximised and accessible 64TB volume on your 5C.