simply software emulation of hardware resources such that one
physical machine can effectively function as several logical
discrete machines. Since this abstraction is done at machine level,
it's often referred to as platform virtualization. This concept has
further been extended to virtualize specific system resources such
as storage volumes, name spaces, and network resources and is
commonly called resource virtualization. While this book will
discuss both kinds of virtualization at various points, it is
nonetheless primarily platform virtualization that is the central
theme of this book. Thus, generic references to virtualization will
always mean platform virtualization.
There are five kinds of platform virtualization technologies and
products as highlighted below by Figure 1.
This book will restrict itself to the first three platform
virtualization technologies: Hard Partitions, Para-Virtualization
and Full or Native Virtualization.
VMware Server and Microsoft Virtual PC are probably the best
examples of Full (or Native) Virtualization and both products are
free. As you move up the virtualization technology ?food-chain?, the
products become increasingly expensive. VMware Workstation offers
just a few more features than VMware Server and it costs about $170.
Para-Virtualization products like VMware ESX range in price from
$1000 to almost $6000 per two processors (Note that Sun's Logical
Domains are free). Moreover, the Hard Partition Virtualization
products? prices tend to be based on the hardware configuration
(i.e. # CPU's) and neither the hardware nor the virtualization
software in these enterprise class machines tends to be cheap.
The meteoric rise in popularity of virtualization is nearly
unheralded. In 2006, Gartner listed five of its top ten strategic
technologies for 2007 to involve virtualization. Such preponderance
in one category has never before or since occurred in their annual
technology survey. Few information technologies have grown so
quickly or had as optimistic a market potential as virtualization as
shown below in Figure 2 by IDC's ?Rise of Virtualization?
If the virtualization market growing 350% in just five years is not
astounding enough, then look at VMware's 2007 stock chart shown
below in Figure 3. In just three months, this stock rose from its
IPO price of $29 to over $104 - an amazing 260% growth in just three
months! That's an astounding stock chart in the post tech-bubble
bust. But virtualization is just that hot - and clearly here to
There are so many universally acknowledged benefits attributed to
server virtualization that it is reasonably unnecessary to provide a
complete and comprehensive list in this book. But let's examine some
of the more relevant advantages, especially as it potentially
relates to Oracle databases.
Better & Faster
Lower Power &
Room Space Needs
Do some of these
points sound familiar? Maybe that's because Oracle's been working on
improving along several of these criteria with their newer database
technologies, such as RAC and Grid. Plus, Oracle's extensive
platform support and features like cross-platform transportable
tablespaces clearly target hardware independence. What that means is
that both virtualization and Oracle's technology trends are quite
harmonious. They are very clearly not at odds.
So as system architects and database administrators, we should look
for opportunities for these various technology solutions to augment,
compliment or supplant each other. And that's not a bad thing. It
simply means that some problems and their solutions are best handled
at various levels and not always within a specific technology such
as within the database itself. For example, which scenario offers
simpler new database deployment and provisioning?
Optimize init.ora or SP-File settings
Define Initial -
Disk Groups & Tablespaces
Roles, Profiles, Policies & Resources
Schemas, Tables, Indexes, Views, Code, etc
Jobs, Programs, Classes, Schedules & Chains
Grants, Contexts, Pub/Priv Synonyms & Links
Deploy Database Virtual Appliance
This is an excerpt from
Oracle on VMWare:
Expert tips for database virtualization
by Rampant TechPress.