Information Technology Reference
In-Depth Information
Virtual Operations
Because each virtual server is stored as a set of files on the host system,
a backup made from a virtual server can be transported to a new host as
rapidly as the media can be mounted. This can speed disaster recovery
immensely, because it eliminates the need for matching hardware and
lengthy configuration. Continuity of operations can also be enhanced
through the use of virtualization, because a large number of virtualized
hosts can be run on less expensive hardware at a backup site, with minor
changes to allocated resources. Although these virtual hosts may operate
at reduced efficiency, the ability to continue normal operations can be a
tremendous benefit to the organization while replacement primary hard-
ware is acquired.
Not all services can be virtualized well, particularly where the full
system resources of a host computer are required for complex resource-
intensive tasks. However, the ability to relocate virtual servers between
hosts by simple file-transfer operations can add greatly to the effective
load balancing of operational resources. Rather than trying to find more
memory to fit into a physical server, a virtualized server can just as easily
be moved to a different system that already has the necessary resources—
taking with it all the configuration settings and even network identities
of the original virtualized host. Many services developed in cloud com-
puting environments can be automatically updated to provide additional
storage, network, and processor power as needed, based on cloud hosting
contractual resource allocation limits.
Plan for the Worst and Hope to Be Wrong
Consolidation, standardization, automation, and virtualization are all
important considerations when planning data center operations. How-
ever, the lead architect must remain aware of internal and external threats
that go far beyond whether the door is locked or the power feeds are
adequate. Contingencies, fallback plans, disaster recovery, and continuity
of operational planning must be included at every step, both during con-
solidation activities and during ongoing normal operations.
When sunspot activity knocked out the power grid across many of the
northeastern states and parts of Canada in August 2003, disaster recov-
ery sites hours away were still within the same area of effect. During the
Gulf Coast evacuation before Hurricane Rita, even sites many hours away
