Customers with active Software Assurance (enrolled in an Enterprise Agreement or under a Select Plus Agreement) for qualifying server products and related CALs are eligible for complimentary server licenses for those products for disaster recovery (DR) purposes.
For each qualifying server license (i) a customer has enrolled in SA and (ii) for which the customer has all related CALs (if required by the product) enrolled in SA, the customer will be deemed to have a second server license under which it may deploy the same product on a “cold” back-up server solely for DR purposes during the term of its Software Assurance coverage. Customers’ deployment and use of software under the DR licenses is subject to the terms and conditions of their license agreement.
(Taken from the Microsoft® PUR Document October 2011)
It is important to note that this is not a Clustered environment. The backup server needs to be brought online once the other server fails and will need to be removed from the network once the other server is restored. Where you can afford a few minutes of downtime in order to bring the back-up server online, this is a viable option.
This Software Assurance Benefit is specifically valuable in the context of Disaster Recover Solutions. Should the primary site fail, the backup servers can be brought online and most recently replicated data can be transferred. New developments in snapshot technologies mean that disruption is fairly limited. A careful analysis of the cost savings of the cold back-up versus the cost of disruption needs to be conducted.