Can I take a new WD Red Pro 18TB hard drive in my drobo 5t?
You will need to ask Drobo Support.
As @TwinTiger said, it’s contact support to be certain, the thing is 16 TiB is one of “those” numbers where things break unless they’ve been written recently enough to allow for passing it. So 16TB is likely to function even if that wasn’t officially covered, but going beyond runs a risk things break owing to the addressing of the number of blocks requiring too many bits of address space.
Hardware limitations might or might not also come into play.
Thank you. I think, it is better to wait for a new firmware version.
The largest drive size tested by Drobo is 14TB, as per this article: Maximum Volume Size and Largest Size Drive
However, the same article shows that the maximum volume size is 64TB. The capacity calculator (Capacity Calculator - Drobo) shows that a volume will reach a size ~50TB if the device is populated entirely with 14TB drives.
So, by necessity, in order to reach the maximum 64TB volume size, drives larger than 14TB will need to be supported. Unless my logic is off.
I had a similar question some time back, and shared the information Drobo Support provided at the time, which may assist you:
Thanks for the details! That answers the question for 16TB drives. I suppose I should open a support ticket to know if 18TB drives would cause an issue.