Private Cloud Higher utilization and additional unit Marginal cost/ benefit

 

Example

you need to run 10 applications (LOB) shall you proceed with Private cloud ?

(the servers cost is used as example only )

each physical server costs $15K (16GB Ram ,6Cores , 1TB Storage )

Now you sum up to 150K

Now we got to the cloud part by using the cloud you removed the physical boundaries with will lead to Higher utilization (I am using the same HW in the physical example)

Graph 1 CPU Utilization

From the graph above you can see that running the ten workload together leaves a Gap witch may be used for additional workloads Two additional workload without impacting the current CPU ,this means that but using the cloud we saved the cost of additional hardware

(the CPU is only one part of the measuring parameters we still have IOps , RAM ) but you get the Idea 

what's acceptable based on your OLA/SLA you may lose one second in response time but you add additional one or two Vms ( you might be shocked what's is acceptable for Management and users )

Now the Marginal cost  of additional unit , what if we added another physical server to the cloud it will not result in adding the server HW Vms , it should add Much Much More because you introduced new factors to the equation.

This the traditional way of thinking

One server 16GB RAM ,6 Core ,1TB = 2 Vms 7GB Ram ,400GB Storage

Two servers (16GB RAM ,6 Core ,1TB) *2  = 4 Vms (7GB Ram ,400GB Storage )

This is the SAFE way but in fact it Should have much more Vms in there because of the probability of all Vms using All the resources at once is almost impossible

So the Cloud should be

Two servers (16GB RAM ,6 Core ,1TB) *2  = 6 Vms (7GB Ram ,400GB Storage )

utilizing Dynamic memory ,memory over commitment , thin provisioning you may get even more .as long you do your study of data growth ,Ram Requirements , processing required .everything should be ok .

Now based on our example we can run 12 to 15 Vm on the private cloud instead of only 10 , and when adding a single server it result in mush higher Ratio. i have seen it reach almost 160% by just adding one server .