How to Tame Virtualization Sprawl - Server Setup (
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Server Setup
Server virtualization
brings industrial production to the data center. One key to industrial design is placing a premium
on creating products that are cost-effective in mass production.
In the case of
server virtualization, IT managers should create a catalog of standard server
configurations from which business managers can choose to install new
applications. For example, Option A could be a single-processor system with 2GB
of RAM and 10GB of storage with a single HA.
Option B could be a two-processor system with 4GB of RAM
and 20GB of storage. The purpose of creating and enforcing a standard catalog
of virtual systems is to prevent customized server sprawl, where each VM is
handcrafted for each application. Maintenance costs associated with customized
servers can eat up much of the cost savings gained from implementing a virtual
infrastructure.
One of the
best ways to ensure that servers are correctly configured and easily maintained
is to provide business managers with enough standard configuration choices to
satisfy most of their application needs and to disallow the return of handcrafted
server customizations that drive up the amount of maintenance labor time.
Implement a
resource SLA (service-level agreement) as part of virtual server instantiation.
Go as far up the organizational chart as necessary to get an authoritative decision
on which applications will be preordained winners and losers in the event of a contest
for available physical resources. Be ready to offer suggestions based on application
type. For example, order processing and the associated database systems are
easy candidates for a guaranteed high SLA because they (presumably) conduct
high-value transactions.
Create only
the number of systems needed to adequately support an application. For
organizations that are new to virtualization, and where there are
virtualization skeptics, plan on allowing at least six months to prove the reliability
of the virtual system creation process. If IT managers can show business
managers that creating servers as needed based on actual performance reports
works, then it will be possible to right-size applications from the get-go. For
organizations that forecast IT budgets based on capacity trends, it is
especially important to accurately measure server use.
It is also
important to ensure that system owner information is up-to-date. The ease with
which virtual systems can be created also makes it easier for server owners to
forget about these VMs. Unlike physical systems that require an extensive
budget process, a physical implementation, an accounting depreciation and
sometimes lease company accountability, virtual systems can easily sit forgotten
and unaccounted for. Aside from taking up virtual processing overhead, these forgotten
systems soak up management cycles because they must be updated. Further, idle
virtual systems can be a security hazard.
One of the
great timesavers of a virtual infrastructure is the ability to instantiate new
servers by cloning an existing system, and it’s important that new systems are
cloned from approved images. It may be quicker to clone a VM from one already
in production, but tracking the lineage of that system to ensure it has the
right security patches and service configurations is extremely difficult. Also
consider that a VM cloned from a system operating in one part of your network
may not be correctly configured to operate in another part. For example, an
internal Web portal system that gets cloned and placed in a DMZ would be a sitting
duck.
IT Infrastructure 
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