1. A method for visualization-centric performance-based volume allocation in a data storage system using a processor in communication with a memory device, comprising: generating, on a display, a unified resource graph representative of a global hierarchy of storage components, including each of a plurality of storage controllers, in the data storage system; wherein the unified resource graph includes a common root node and a plurality of subtree nodes corresponding to each of a plurality of nodes internal to the plurality of storage controllers, the common root node and the plurality of subtree nodes ordered in a top-down orientation; wherein generating the unified resource graph includes generating a visual representation of an aggregate summary measure for the common root node and each of the plurality of subtree nodes; wherein the aggregate summary measure includes a gap value corresponding to an estimate of a new workload amount that may be allocated in one or more subtree nodes of the common root node without exceeding performance and visual space limitations of any of the subtree nodes of the common root node; and performing scalable volume provisioning of an existing or new workload amount by graphical manipulation of at least one of the storage components represented by the unified resource graph based on an input, said graphical manipulation comprising: dynamically expanding and reducing a number of displayed subtree nodes in the unified resource graph based on one of an estimated screen size and an estimated window size of the display, and if reducing the number of displayed subtree nodes: determining a position of a cursor on the display, and collapsing a subtree node furthest from the position of the cursor into the common root node.