What Is Erasure Coding?

Erasure encoding is a simple and fast method to encode data in a lossless format. 

Erasure code offers a failure-free storage environment. It is a form of information dispersal algorithm that allows data to be distributed across multiple storage devices. The idea behind erasure coding is simple: rather than writing data to storage in its entirety, it is broken into smaller chunks, which are then used to reconstruct the original data if needed. 

Erasure codes can work at different levels of granularity; for example, an entire file can be encoded as K chunks, or a file system block can be encoded as K-independent blocks.

The main advantage of the erasure encoding is that it can be decoded even if some blocks are missing, or not received at all. It is used in different communication systems to improve the robustness against transmission errors.

What Is the Difference Between RAID and Erasure Coding?

For some reason, RAID and erasure encoding are mistaken as the same things. In reality, both are quite different. 

RAID is mostly used for servers and other large storage devices. It mirrors your data across multiple hard drives, so if one drive fails, you have a backup. The downside is that it is more expensive than erasure encoding and utilizes more space on each drive.

RAID doesn't actually protect the data on your drives from being read by another computer. Anyone who can get their hands on one of the drives can still see all your information. Erasure encoding does exactly what it sounds like: It scrambles the data so no one can read it without the right key.

Erasure encoding breaks your data into segments and expands and encodes it with redundant information. On the other hand, data isn’t broken apart in RAID.

Benefits of Erasure Coding

Erasure coding is a way of storing data in a reliable manner that can be used to recover the original data should any portion of the storage medium become damaged. There are many benefits of erasure encoding that make it an attractive alternative to other data storage methods. 

The key features of erasure coding include:

Scalability – This technique can be applied to both small and large amounts of data.

Reliability – Since it keeps only fragments of data, the original one can be recovered even if some of the storage media has failed.

Cost-effective – This technique is cost-effective when you consider the cost savings associated with not needing to purchase additional backup and recovery software.

Speed – The time needed to recover from a single failure is much shorter when erasure encoding is used compared with other methods.