  The continuously increasing amount of digital data generated by today's
society asks for better storage solutions. This survey looks at a new
generation of coding techniques designed specifically for the needs of
distributed networked storage systems, trying to reach the best compromise
among storage space efficiency, fault tolerance, and maintenance overheads.
Four families of codes tailor-made for distributed settings, namely - pyramid,
hierarchical, regenerating and self-repairing codes - are presented at a high
level, emphasizing the main ideas behind each of these codes, and discussing
their pros and cons, before concluding with a quantitative comparison among
them. This survey deliberately excluded technical details for the codes, nor
does it provide an exhaustive summary of the numerous works. Instead, it
provides an overview of the major code families in a manner easily accessible
to a broad audience, by presenting the big picture of advances in coding
techniques for distributed storage solutions.
