1. Data center tiers are established rankings for the performance of servers which house data and information.
2. Data centers are ranked from I to IV, with I being the worst-performing of the four and IV being the best-performing.
3. The Uptime Institute’s Tier Certification is the independent measure through which ratings are judged. It determines the criteria for each tier and lists several values that collectively make up what constitutes the standards of data center tiers.
KEY FACTORS INCLUDE
1. Performance: Standards are performance-based, meaning any solution which meets the requirements for availability, redundancy, and fault tolerance is acceptable.
2. Technology neutral: Tiers don’t require specific technologies in order to be classified, mostly because new advanced technologies consistently disrupt the digital transformation landscape.
3. Vendor neutral: The brand of technology used in a data center isn’t considered as a factor in determining the tier, meaning centers are judged purely on their capabilities.
4. Now we’ve gone over the purpose of data center tier ratings, let’s take a look at each individual rating and see what you can expect from each one in terms of uptime and redundancy.
5. Below are the listed data center redundancy tiers as outlined by the Uptime Institute with their data center tier classification system.
TIER 1 DATA CENTER (BASIC CAPACITY)
1. A Tier I data center is the lowest-rated tier. It’s above putting a stack of servers in a closet in your office, but as far as performance goes, Tier I is at the bottom of what you can get from data center tiers.
2. This is because a data center adhering to Tier I standards can only guarantee an uptime of 99.671% and lacks IT equipment that supports redundancy.
3. Tier I data centers require no redundancy, meaning they don’t have to offer basic backup needs, like a simple power and cooling setup and Uninterrupted Power Supply (UPS), and they fall short of the standards of the other tiers.
4. They are typically best suited to very small businesses looking for an affordable option. There can be up to 1729 minutes of annual downtime.
TIER 2 DATA CENTER (REDUNDANT CAPACITY COMPONENTS)
1. Tier II data centers offer all the capabilities of Tier I, but with added redundancy options.
2. Like Tier I, Tier II systems will have a single power input, but with additional fail-safes for backup.
3. These fail-safes include UPS modules, chillers, pumps, and energy generators.
4. Tier II centers offer a marginally higher uptime of 99.741%, which translates to no more than 1361 minutes a year.
5. Tier I and Tier II can be thought of as similar in most respects, with Tier II being the more robust of the two.
6. Both types of data centers lack the performance capabilities found in Tiers III and IV, but still offer a good balance of performance and affordability.
7. Much like Tier I, Tier II data centers are commonly utilized by small businesses that want a cost-effective option for their data storage needs.
8. These data centers are not totally redundant, but they are more reliable and secure than Tier I alternatives.
TIER 3 DATA CENTER (COMPREHENSIVE REDUNDANCY)
1. This is where data center tiers start to get a little more serious. SMBs generally prefer to use at least a Tier III-rated system for the far superior redundancy protections offered.
2. There is a significant jump in uptime from Tier II, with Tier III offering annual uptime of 99.982%. This means that your network will experience a maximum of 95 minutes downtime per year.
3. The improved times owe to the requirements for more comprehensive redundancy capabilities.
4. Whereas Tiers I and II only require one path for power and cooling, Tier III requires an additional redundant path for backup which kicks in in the event of failure.
5. Tier III systems are not totally redundant, due to them often being reliant on or sharing components which are not fully independent to the data center—effectively meaning that it could be adversely influenced by external mishaps. This is the case for Tiers I, II, and III.
6. These types of data centers are favored by SMBs whose IT operations need additional fail-safes over those basic protections offered by the lower tiers.
TIER 4 DATA CENTER (FAULT TOLERANT)
1. Tier 4 data center security marks the highest standard for data centers—usually utilized by businesses that require constant availability, which is most businesses today.
2. They have an uptime of 99.995%, meaning annual downtime of no more than 26 minutes.
3. They also feature 2N and 2N+1, fully redundant infrastructure—the main difference between Tiers III and IV.
4. 2N redundancy means there is a completely mirrored system on standby, independent of the primary system. This means that should anything happen to a component in the main data center, there is an identical replica for every component ready to pick up the slack. This is by far the most robust form of security that can be employed.
5. All components are supported by two generators, two UPS systems, and two cooling systems. Each path is independent of each other, meaning that a single failure in one will not cause a domino effect with other components, as is the case with lower tiers.
6. Tier IV data centers have a power outage protection of 96 hours, and this power must not be connected to any external source and must be independent.
7. This is what’s referred to as “fault tolerance”—a capability which means that in the event of a system failure, IT operations aren’t affected in any way.
8. Unlike Tier III, Tier IV data centers are prepared for unplanned maintenance—businesses which use Tier IV systems will often be unaware that an outage has taken place at all.
DATA CENTER TIERS BY UPTIME
1. Tier I: 99.671% uptime; maximum downtime of 28.8 hours per year
2. Tier II: 99.741% uptime; maximum downtime of 22.7 hours per year
3. Tier III: 99.982% uptime; maximum downtime of 1.6 hours per year
4. Tier IV: 99.995% uptime; maximum downtime of 0.4 hours per year
Source:
https://www.impactmybiz.com/blog/data-center-tiers-explained/
