An engineer sees the instance type "m6a.large" in a couple of the fleet's launch templates and wants to decode the name to understand what it commits them to. Which statement correctly decodes it?
- "m6a" tells you only the vCPU count; the "large" suffix determines the instance family
- The "6" indicates the number of CPU cores, and "a" indicates the AWS Region the instance type is available in
- "m6a" specifies the operating system license included with the instance, and "large" specifies the pricing model (On-Demand vs Reserved)
- "m" identifies the instance family (general purpose), "6" identifies the generation number within that family, and the additional letter "a" indicates a processor variant (AMD-based, in this case), while "large" is the instance size within that type
Why D? And why not the others?
Correct answer: D. "m" identifies the instance family (general purpose), "6" identifies the generation number within that family, and the additional letter "a" indicates a processor variant (AMD-based, in this case), while "large" is the instance size within that type
AWS's instance type naming convention encodes several independent pieces of information in a compact string: the leading letter identifies the instance family (for example, "m" for general purpose, "c" for compute optimized, "r" for memory optimized), the following number identifies the generation of that family, and additional letters appended before the size (such as "a" for AMD-based processors, "g" for AWS Graviton/Arm-based processors, or "n" for enhanced networking) describe optional processor or capability variants; the final component after the period, such as "large", specifies the instance's size within that type. This means "m6a.large" is a 6th-generation, general-purpose, AMD-based instance at the "large" size. The option claiming "m6a" only encodes vCPU count and that size determines instance family reverses which part of the name carries which meaning. The option claiming the number encodes core count and the trailing letter encodes a Region confuses generation numbering and processor-variant letters with concepts (exact core counts, Region availability) the instance type name doesn't directly encode at all. The option describing the name as encoding OS licensing and pricing model is wrong because neither of those is part of the instance type string; both are chosen separately at launch time.
Source: AWS documentation: Amazon EC2 instance types — instance type naming conventions