One Rack Data Center - 3000 VMs

Lets say we had a requirement for 3000 VMs with the average VM being 2 vCPUs / 4 GB memory / 150GB storage. How many servers racks would we need?

Assuming we use the latest generation Intel Xeon CPUs and new Intel Ruler Storage we would need:
Servers:
      3000 VMs x 2 vCPUs / (56 pCPUs x 4 vCPU:pCPU ratio) = 26 x 1 RU servers 
Storage:
       3000 VMs x 150GB = 450TB in 1 RU Ruler Storage Appliance
Backup:
       450TB x 3 (compressed/deduped) / 900TB Backup Server = 2 x 4 RU Backup Servers

Total = Servers 26 RU + Storage 1 RU + Backup 8 RU = 35 RUs...Just one rack for 3000 VMs.

Servers:
Latest generation Intel Xeon CPU servers support 56 CPU cores (112 threads):
1 RU Server: http://www.dell.com/en-us/work/shop/povw/poweredge-r640 (Up to 1.5TB of memory)
2 RU Server: http://www.dell.com/en-us/work/shop/povw/poweredge-r740 (Up to 3TB of memory)
https://www.spec.org/cpu2006/results/res2017q3/cpu2006-20170626-47239.html

Storage:
https://newsroom.intel.com/news/intel-delivers-storage-transformation-new-ssd-form-factor-innovative-designs/
Intel's new EDSFF (Enterprise & Datacenter Storage Form Factor), with the simpler working name as 'Ruler', mainly because it bears a resemblance:

Backup with 90 x 10TB disks:
http://www.supermicro.com/products/chassis/4U/946/SC946ED-R2KJBOD

Data Centre:
If we only need one rack for 3000 VMs why build/maintain our own data center? Equinix charge less than $2000/rack/month and have data centers all around the globe. They also have fast 10Gb+ networking between their data centers in the same country.

DR:
Use same infrastructure in another data center. Have high speed 10Gb+ networking between data centres. For replication options are:
- Virtualisation replication such as vSphere replication, Zerto
- Server replication such as CloudEndure
- Database replication such as Oracle Data Guard, SQL Server Replication, Mysql Replication
- Storage replication such as ZFS replication