When i have disks lower than 8TB, i can increase the storage when i allocate more using diskpart,
but as soon as I hit 8TB i cannot extend that volume, even if i create a 10TB volume and extend it, it shows in windows and is usable, but cannot extend from the original created partition.
this happens for existing storage and new ones i create.
Background:
4x Hyper-V running Server 2016 Datacenter
Storage: Dell CT-SC4020 with 66TB
Storage Clustered to c:\ClusterStorage
Create a new 7TB Volume

Set "Online" and "Initialized" in Disk Management and formatted to NTFS (GPT)
now at this stage if i do NOT add it to the Cluster Storage, i can extend it beyond 8TB
Add it to Cluster Storage


Added an extra 2TB to storage

diskpart list volume

try and increase max storage, generates in the error
"DiskPart has encountered an error: Incorrect function."