In Chain Data Replication, the non-official data set distributed among many disks provides for load balancing among the servers within the data warehouse.
Blocks of data are spread across clusters and each cluster can contain a complete set of replicated data. Every data block in every cluster is a unique permutation of the data in other clusters.
When a disk fails then all the calls made to the data in that disk are redirected to the other disks when the data has been replicated.
At times replicas and disks are added online without having to move around the data in the existing copy or affect the arm movement of the disk.
In load balancing, Chain Data Replication has multiple servers within the data warehouse share data request processing since data already have replicas in each server disk.   _{Your Comment}