After deploying a Teradata Database single-node or multi-node system, you can expand the amount of system storage while maintaining the AMP count. Expanding storage increases the storage capacity of the premium volumes but does not affect the storage capacity of the system.
A system in its original (fully scaled-in) state distributes an equal number of subpools and data disks to all nodes in the configuration; however, the number of subpools and data disks varies between nodes on a scaled-out system. Therefore, when expanding storage on a scaled-out system, the system always adds a certain number of TBs per node based on the original (base) node count. For example, if you originally deployed a 2-node system and later scaled out to 6 nodes, and then you expand storage by 2 TBs per node, the system storage increases by 4 TBs based on the original 2-node configuration – not 12 TBs based on the current 6-node configuration.
Data disk expansion is a non-reversible operation.