Sorry for the long title.
There is two reasons as to why you would be taking this exam. The first is because you want to achieve the CCNP Datacenter title, or the second is because your company requires you to, so they can achieve the Unified Computing Technology Specialization.
My reason was the second, but the Cisco Datacenter track is something I am interested in in the long run.
If your going for the partner route like me, you are not required to have the CCNA DC under your belt. But if you want to achieve the CCNP DC, you need to complete the correct pre-reqs, which can be found here.
The exam is 90 minutes with around 70 questions. The recommendation is to undertake the Designing Cisco Data Center Unified Computing course from an authorised Cisco Learning Partner. Which is exactly what I did, and then sat the exam straight after.
I will blog about the course separately.
So the exam was the usual Cisco, its made of majority multiple choice questions, and I also had two small testlets.