I have three disks. Disk0 (boot), Disk1 and Disk2. Disk 1 and 2 are both unformatted and unallocated drives. I am trying to mirror Disk0 to Disk1. They are both Dynamic and are both the same size (1TB). When I select Disk1 to be the mirror I get the error "There is not enough space available on the disk(s) to complete this operation". I have spent several hours searching for a solution but have not found one. Why do I get this error when they are both the same size?

EDIT: Shrinking the volume size on the boot disk by 100MB allowed me to get past this error. From what I read the mirror drive needs to be the same size or larger than the boot drive. So I am confused why that change worked. However, I now get the error " all disks holding extents for a given volume must have the same sector size and the sector size must be valid". I believe this is because the drives are different and one has 512B and the other is the Advanced Drive that is 4KB. What the different sector sizes cause both problems? If I got the same disks would both issues go away?