Windows Server 2012 - Storage pools with different disk size

I have 2 disks (1TB + 1.5TB) in a Storage Space. Free space shows up as 2.27TB.

I create a new Virtual disk with Simple layout (no redundancy). Maximum size for the virtual disks stops at 1.82TB (seems to be the 2TB drive limiting). I can then also create a second virtual disk of the remaining size.

Why can't I create a 2.27TB disk, isn't that possible?

I found a workaround: Add disk1 to the pool, and create a fixed Virtual Disk with a NTFS Volume (sized to the max of disk1). Then I add disk2 to the storage pool and extend the Virtual Disk, and extend the NTFS Volume. Then I can use all available storage from disk1 & disk2 in one NTFS volume.

I have to do it in two steps.

Can anyone confirm this behavior, or explain it to me?

Not sure why, but the UI seems to default to mirror striping for disks of equal size in Windows Server 2012 R2. In my case, 4TB + 4TB + 2TB (10TB total) created a virtual disk of 6TB, i.e. it seems two 4TB disks were used in RAID 1.

To solve this, you can use the New-VirtualDisk PowerShell command, using the following parameters:

// this will create a "Simple" JBOD virtual disk over the entire storage pool
New-VirtualDisk 
  -FriendlyName Your_new_vdisk_name 
  -StoragePoolFriendlyName Your_existing_pool_name
  -ResiliencySettingName Simple
  -NumberOfColumns 1
  -UseMaximumSize

Make sure you remove any previous virtual disks from the pool. Also, you will need to refresh the Storage Pools page to see these changed after running the command.