Nutanix Certified Associate Practice Exam

How does erasure coding work?

1. Looks within a file and saves unique iterations of each block

2. Encodes a strip of data blocks on different nodes and calculates parity

3. Condenses sequential streams of data or large I/O sizes when written to the Extent Store

The correct answer is: Encodes a strip of data blocks on different nodes and calculates parity

Erasure coding is a data protection mechanism that enhances data reliability by spreading data across multiple storage nodes. The concept operates by dividing a file into data blocks and then generating redundant parity blocks. In this process, data blocks are encoded into strips distributed across different nodes within the storage cluster. This method allows the system to recover lost data by using the remaining intact data blocks and the parity information. By calculating parity for the segments of data, erasure coding not only preserves the original data but also provides fault tolerance. If a node fails, the data can be reconstructed using the remaining data blocks and their associated parity. Essentially, this approach ensures that data remains accessible and intact even in the case of multiple node failures, making it a highly efficient and resilient solution for data storage. Other choices, while they touch on various aspects of data handling, do not accurately describe the mechanism of erasure coding. The first option discusses saving unique iterations of data blocks, which does not align with how erasure coding functions. The third option mentions condensing streams of data, which relates to data compression rather than the encoding and recovery processes fundamental to erasure coding.