Please be advised that we do not support re partitioning or re-sizing of any volumes with disk utility or any other 3rd party hard drive utility on the fly. This can lead to file system issues, that can be unrecoverable.
Disk utility can be a wonderful tool to verify and repair volumes, but we do not recommend using it to re-size or re partition in any form. Please do not do this when directly accessing a Drobo Volume.
When setting up your Drobo, it is always best practice to format and begin your volume using dashboard. If your volume size needs adjustment, you will need to copy the data to another location, so that you can reformat and recreate the volume to the size you need.
The ability to format partitions with more granularity and resize partitions (at least expand them) is very sadly missing in Dashboard and should be at the top of your “to do” list. Some users will actually want multiple, smaller partitions, not one big one, but later need to expand them. Most especially, some users (like me) want the partition size to reflect the actual drive space available, not a potential number if I were to install drives of a capacity that is currently unavailable.
Fortunately for me, I formatted my Gen3 with 4 x 6TB drives when 16TB was the max and that very closely matched the real drive capacity, so the capacity of one volume is only slightly smaller than the real drive capacity, and I have dismounted the other.
My Drobo has multiple volumes, and once I had a volume get corrupted. Neither Disk Utility or Disk Warrior could repair it. At the time, Data Robotics said the only thing I could do was move all my data off and Reset the whole Drobo, starting over. Surely there is a better way now? I have five 3TB drives in my new Drobo, and if one of my volumes got corrupt, it’s much harder to find storage to move all my data somewhere else and start over.