I had the opportunity to tour a private Tier 4 data center earlier this week. One of the first and one of the largest to open in Canada. Very impressive.
Data centers fall into two main categories: private and public. A private data center is managed by the organization”™s own IT department, and it provides the applications, storage, web-hosting, and e-business functions needed to maintain full operations. Public data centers provide services ranging from equipment colocation to managed web-hosting. Clients typically access their data and applications via the internet.
Data centers are built with carefully engineered support infrastructures:
- Power supply and backup
- Cooling and environmental control
- Fire and smoke systems
- Physical security
- Connectivity to outside networks
- Network Operations Center
The more “mission critical”? the application is, the more redundancy, robustness, and security required. Data centers can be classified by Tiers, with Tier 1 being the most basic and inexpensive, and Tier 4 being the most robust and costly. According to definitions from the Uptime Institute and the latest draft of TIA/EIA-942 (Telecommunications Infrastructure Standard for Data Centers), a Tier 1 data center is not required to have redundant power and cooling infrastructures. It needs only a lock for security and can tolerate up to 28.8 hours of downtime per year. In contrast, a Tier 4 data center must have redundant systems for power and cooling, with multiple distribution paths that are active and fault tolerant. Access should be controlled with biometric readers and single-person entryways, gaseous fire suppression is required, the cabling infrastructure should have a redundant backbone, and the facility can permit no more than 0.4 hours of downtime per year.
Tier 1 or 2 is usually sufficient for enterprise data centers that primarily serve users within a corporation. Financial data centers are typically Tier 3 or 4 because they are critical to economic stability and must meet higher standards set by government. Public data centers that provide disaster recovery / backup services are also built to higher standards.
The data center that I toured was certainly world class and state-of-the-art. An impressive technical achievement.