Windows 11 possible issue with Disk Management

[Murray Sobol]

I have a Probox NAS with 2 drives populated.
The first drive is a 4GB drive with no issues.
The second drive is a 8GB drive but shows only 2048GB allocated and 5404GB unallocated.
When I launch Disk Management and select the second drive the option to "extend" the drive does not exist.
AFAIK the Probox firmware is up-to-date.
Any ideas??

 

[Murray Sobol]

I do NOT wish to create an additional drive, I would like to expand the second drive to its maximum capacity.

 

[rfsmith7]

I assume your drives are 4TB and 8TB.

Sounds like the second drive is configured as MBR not GPT. MBR drives have a 2TB limit.

 

[Murray Sobol]

Thanks rfsmith7, that was the problem, I was looking at the "wrong" area for the source of the problem.