Largest Harddrive Size That can be used

Can Drobo Pros use 4TB hard drives?

i searched the knowledge base for 4TB, and the first result was this:

so yes.

Extending this thread a little bit deeper:

When I set up the DroboPro initially, I had to select what overall size I expected it to be. I believe I set it up to be the largest available at that time - 16TB, if memory serves.

My question is: With the latest firmware allowing the use of 4TB drives, does that mean simply replacing the eight 2TB drives I have in there now with eight 4TB drives, the Drobo Pro will allow for 32-ish TBs of storage?

Or is the process more convoluted, requiring a “Start from scratch” approach. (This would be pretty difficult, simply because of the need to back up the data and re-initialize the system to configure the greater capacity.)

Thanks in advance,


you chose to have a 16TB volume

I believe that is the limit

but even now, regardless of what disks you have in there, you can create multiple 16Tb volumes (because you have the pro)

I forget whether you are limited to 16 or 32 or 64 volumes… but basically its more than enough[hr]
and you don’t need to start over to create a second third or fourth volume

I was told you can run more than one volume as well by Drobo tech, however, I can’t figure out exact procedure, and are very nervous about any data loss potential. Yes, I backup to BackBlaze (crazy unlimited cloud storage…/amazing!) but counting on it would be super time consuming (It did work for silly file deletion / damage quite easily).

I have 8-bay Pro using double redundancy with:

17 TB of Drives
1 Volume
16 TB Max Capacity
Used 8.20 TB
Free 1.43 TB
Total 9.64 TB

Just got a warning that I should replace the smallest drive (1 TB) that turned YELLOW with a larger one because space it getting low. When I did, a different drive turned RED (2 TB) with the warning that double projection can no longer be sustained and I should replace it with a larger one. Super confusing.

So I replaced the removed 1 TB everything went GREEn for a moment, then YELLOW reporting I can use it while protect is completed.

  1. May I just add a new volume with another max of 16 TB without effecting the existing volume and it data?
  2. Will is start the new volume with the access 1 TB that now exists?
  3. Will any other larger capacity drive swaps flow into the new volume without intervention?
  4. If all of that is true, should I wait until data projection is done? Or, go ahead now?

Thanks in advance for the knowledge and guidance.