Page 1314 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

primary site.

If an organization wants to maintain a hot site but wants to reduce the
expense of equipment and maintenance, it might opt to use a shared
hot site facility managed by an outside contractor. However, the

inherent danger in these facilities is that they may be overtaxed in the
event of a widespread disaster and be unable to service all clients
simultaneously. If your organization considers such an arrangement,
be sure to investigate these issues thoroughly, both before signing the
contract and periodically during the contract term.

Another method of reducing the expense of a hot site is to use the hot
site as a development or test environment. Developers can replicate

data to the hot site in real time both for test purposes and to provide a
live replica of the production environment. This reduces cost by
having the hot site provide a useful service to the organization even
when it is not actively being used for disaster operations.

Warm Sites

Warm sites occupy the middle ground between hot and cold sites for
disaster recovery specialists. They always contain the equipment and
data circuits necessary to rapidly establish operations. As with hot

sites, this equipment is usually preconfigured and ready to run
appropriate applications to support an organization’s operations.
Unlike hot sites, however, warm sites do not typically contain copies of
the client’s data. The main requirement in bringing a warm site to full
operational status is the transportation of appropriate backup media

to the site and restoration of critical data on the standby servers.

Activation of a warm site typically takes at least 12 hours from the time
a disaster is declared. This does not mean that any site that can be
activated in less than 12 hours qualifies as a hot site, however;
switchover times for most hot sites are often measured in seconds or
minutes, and complete cutovers seldom take more than an hour or
two.

Warm sites avoid significant telecommunications and personnel costs

inherent in maintaining a near-real-time copy of the operational data