The Cloud Makes It Rain Money: The Business in Cloud Computing - Deploying and Managing a Cloud Infrastructure - page 367

Warm Backup A warm backup site is already stocked with hardware. However, to restore
the service, the latest backups from the offsite storage facility must be delivered and bare
metal restoration must be completed before the recovery process can begin.
Hot Backup Hot backup sites are really a virtual mirror image of the current data center,
with all systems configured and waiting only for the latest backups of data from an offsite
storage facility. A hot site can often be brought up to full operation in significantly less
time, typically a few hours. However, this type is the most expensive of them all.
Backup sites can come from three different sources:
■ Companies specializing in providing disaster recovery services
■ Other locations owned and operated by an organization
■ A mutual agreement with another organization to share data center facilities in the
event of major disasters or failures
Each approach has its pros and cons:
Using Disaster Recovery Specialists Contracting with a disaster recovery specialist often
comes with access to professional skills, which can help in guiding organizations through
the process of creating, testing, and implementing a DRP.
Using Another Facility of Your Organization Using space in another facility owned and
operated by your organization is cost effective in terms of capital expenses, but stocking
the backup site and maintaining its readiness is still an expensive proposition. Nevertheless,
if the site is being used for other operations and projects, then the cost of operation can be
covered by funds from those operations and projects. In fact, this empowers an organiza-
tion with geographical diversity, such that it has sites in two or more distant geographical
regions that maintain backups for one another. It provides a number of technical advan-
tages as well:
■ Additional redundancy
■ Network proximity
■ Performance enhancement
■ Legal diversity, getting around regional legal issues
Sites in distant geographical regions are more likely to survive a disaster, especially a
natural one, if only because of their different locations.
Sharing Data Centers with Another Organization Last, crafting an agreement to share
data centers with another organization can be inexpensive, but it may create a lot of admin-
istrative and managerial friction. Long-term operation might not be possible because the
operation of the host's facility might different than the other organization's operations.
The selection of the backup site is therefore a compromise between cost and the needs of
the organization.