This article can also be found in the Premium Editorial Download "Storage magazine: Hot, warm, cold: Pick the right disaster recovery site."
Download it now to read this article plus other related content.
By contrast, organizations with more restricted budgets have a huge variety of options for protecting their data centers and critical information. These options
With regard to externally provided solutions, the definitions of cold, warm and hot sites are many and varied. While there are currently no official standards for alternate sites, international standards like ISO/IEC 24762:2008, Guidelines for Information and Communications Technology Disaster Recovery Services, address IT DR services provided by vendors and provides a good set of criteria for evaluating these options.
Brown, who has been involved in alternate site planning and implementation for more than 30 years, likes to use the following definitions: “A hot site is a fully operational data center that also has live customer data. A cold site is a type of data center that has no technology installed. It will have power, HVAC and communications in place. A warm site is an equipped data center, but without customer data.” In each case, the equipment in place at alternate site facilities is shared by multiple users. If there are multiple disaster declarations, Brown added, the response is usually first come, first served. Some companies will pay extra to have dedicated equipment available only to them.
The key criteria most likely to influence the selection of a particular alternate site arrangement include internal vs. external resources, RTO and cost vs. risk. For example, it would be very good to mirror your data in real-time to an offsite facility, but the cost to do that may be prohibitive. Brown estimates that data mirroring costs can be up to 10 times the cost of a hot site.
In this option, costs are incurred for the service used, the data mirroring technology and the network bandwidth (usually fairly high) required to transmit large volumes of data in real-time. Can your organization risk data loss by using a data protection solution that doesn’t provide real-time mirroring? Because alternate sites are usually shared facilities, Brown noted, they represent a shared risk -- unless you decide to pay additional fees for dedicated access to recovery resources.
Another important consideration is make vs. buy. Factors that can influence a make vs. buy decision include RTO, cost and risk. According to Brown, an internal system done right is a far better solution, but it’s also the most costly option. It’s always better to do an internal solution, but can you afford the cost vs. the risk?
This was first published in January 2012