My personal adventures in the quest for virtual perfectness.
I got a question from @repping yesterday which got me thinking. His question was: "Do you know a good site where I can find memory prices for enterprise hardware.". Later it became clear he wanted to use that price to calculate chargeback for memory. He wanted to know the amount/GB. My fist reaction was: well, looking at the total amount of memory in combination with certain size DIMMs - the price rises with larger and larger DIMMs.
I think Dell uses a quite transparent site, with reasonable prices. Let's take a typical server, an R720 which can hold 2 XEONs and hold 24 DIMMs. Here is a table with the current price at time of writing this post:
|2GB||70 euro||35 euro|
|4GB||77 euro||19,25 euro|
|8GB||130 euro||16,25 euro|
|16GB||350 euro||21,88 euro|
|32GB||2.100 euro||65,63 euro|
So if I would buy a server right now, and I want "the best bang for the buck", I should go for 8GB DIMMs - stated that 192GB of memory would be sufficient.
But this got me thinking: what price should be used to charge a customer, what would be reasonable? A VM with 2GB: use 70 euro, or use 32,50 euro? Also, if I would need monster VMs, buy the 32GB DIMMs since I need some VMs with 256GB of mem... Would I use the 65 euro/GB for chargeback also for smaller customers. And what if I would upgrade to newer hardware...
And would you charge for configured memory or actual in use, including memory saving techniques.
This isn't only relevant to memory, but also CPU, disk space usage (perhaps even IO usage), network vlan usage (perhaps even IO usage). And don't forget the maintenance contracts for hardware, physical racks, power, cooling, building, backup, monitoring tooling, antivirus. Then there are license costs, FTE's designing, configuring and supporting the infrastructure. What about the design impacts: n-1 or n-2 solution where cluster sizes also make a change in total capacity you can run. And test equipment... And disaster recovery site...
Chargeback isn't easy! But what would be your solution for calculating the price/GB?