Whoever wrote the new volume wizard in Windows Server 2012 R2 had a odd sense of humor (or was just not very good at writing code). I mean, 1.54 TB is of course not equal to 1.54 TB, right?
Anyway, this week is book-writing week, and when me and my very good friend and partner in crime, @mikael_nystrom was deplying one of the Hyper-V hosts, a HP ML350p, we run into the "fun" wizard. We had just created a new virtual hard disk, and a storage pool (two-tiered, mirror) of two SSD and six SAS disks, and was about to create a volume when this friendly wizard page refused to continue.
Fixing the problem is easy, just change TB into GB, type in the correct value, and off you go. (note that the "," is only a thousand-separator).