Database Reference
In-Depth Information
Chapter 1. Virtualization: The New World Order?
It is not the strongest of the species that survives nor the most intelligent
but the one most responsive to change .”
—Charles Darwin
This chapter is about a new computing paradigm where your SQL Server databases are
virtualized. In this chapter, we discuss what it means to break the tether of the database
from the physical server. We use real-world examples to demonstrate how a virtualized
database will better enable you to respond to the needs of your business, day in and day
out.
Virtualization: The New World Order
Imagine this: It's Friday afternoon, a beautiful spring day, and you are driving down the
highway talking on your cell phone. Hands free, of course—we know you would never
consider doing it any other way. As you are talking on the cell phone, do you think about
what cell tower you are using? Do you even give it a second thought? The short answer
is “no,” as long as your cell phone keeps working, that is all you care about.
Why do we as database professionals care what physical server we are using as long as
our SQL Server database gets all the resources it needs, when it needs those resources.
Isn't that what really matters?
Now imagine that each cell tower represents a physical server. Imagine the cell tower
you are currently on is overloaded. Instead of getting the dreaded message “All lines are
busy right now, please try your call later,” in a virtualized infrastructure, your phone
call would be re-routed to a cell tower that had capacity so the call goes through
uninterrupted. In this new way of computing, your database will find the next “best
available” cell tower to move to, so that you are able to place your call. In this new
way of computing, you would be better able to provide service-level guarantees not
possible before database virtualization. In a virtualized infrastructure, you have
resource mobility. You can use technologies such as vMotion within VMware to move
your database to another server while it is in use. Just as your cell phone moves cell
tower to cell tower, so can your database move server to server when more or fewer
resources are needed.
Now imagine that a cell tower you are using suddenly becomes unavailable. Perhaps
lighting has struck it. In this example, your cell phone would reassign itself to another
cell tower to ensure you would still be able to make more phone calls. Worse case,
your phone might roam to another carriers infrastructure. In a virtualized infrastructure,
your database would restart itself on another server and continue processing its
 
 
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