A cluster file system is a system that clusters multiple independent nodes (servers) over the network and delivers it as a single storage unit. While RAID groups employ multiple disks to multiply the capacity, speed and stability, the cluster file system groups the multiple storage servers to enable high capacity (up to hundreds of TB), high bandwidth (up to hundreds of Gbps), and high availability (24*7 service), something that is difficult to accomplish with a RAID group.

Typical cluster file systems emphasize high capacity and stability, since they are designed with the application as the main use. Therefore, when applied in the Internet service environment, in which traffic (delivery) is the key issue, problems can arise in handling the natural increase in traffic while maintaining high availability (24*7 service) as the number of users increases.

The cluster file system used by CDNetworks is optimized for digital content services and offers high traffic volume handling capability and high availability, while ensuring large capacity and stability.

The following table shows the characteristics of digital content. For UGC video, a typical example of digital content, content uploaded (written) by a relatively small number of users is viewed (read simultaneously) by a large number of users. CDNetworks¡¯ cluster file system reflects that fact by allocating more resource cost to technically process the write and emphasizing the simultaneously read content in order to make the Internet service environment run more efficiently.