Cannot create Virtual Disk mirrored because it claims I do not have enough Physical Disks

I am trying to create an SOFS file server for a VDI environment.  Here is my configuration

2 node cluster

DNS 1640 JBOD with 24 SAS drives

4 HBAs, 2 on each server.  Both connected to JBOD for redudancy

I am able to see all the drives and create the Storage Pool.  Howevver when it comes to creating a VHD and selecting Mirror, I am getting an error stating that I do now have enough disks for that configuration.  There are 24 disks in my Storage Pool, two used as hot spares.  Is there anything I have to do with the disks once they are in the Storage Pool?