Cutting cost at the data center

I guess the biggest issue with most data centers is cutting its cost. The main idea behind this would be to maximize utilization, shutdown hardware which is not necessary.

We need a mechanism in database & applications to run in a minimal mode. I would say the entry interfae for any application (web or otherwise) would be its login function. Databases and application servers should have the capability to run in minimal/ login mode. No need to keep a large chunk of database in memory, just keep the login fraction. As soon as someone logs in, it triggers other tables/ functions to load.

Same goes with application server, the application should load and run only the login interface. Rest of the modules should be loaded once a user logs in. Other objects/ modules should not be anywhere in memory.

In order to do this, server need to have a combination of old fashioned hard disks (HDD) and a solid state storage (SDD). Fetching data from SDD definitely faster than HDD so OS should store data should SDD where as raw data should be stored in HDD.

I guess this will add another layer of memory to a complicated system but such passive data writes will keep only bare minimum OS & hardware components working. Thus saving electricity.