To expand a Starter X-Brick cluster (which typically begins with one X-Brick) to an eight X-Brick cluster, a total of three expansions are required. Each expansion step in XtremIO can typically double the number of X-Bricks, thus:
First expansion: From 1 X-Brick to 2 X-Bricks.
Second expansion: From 2 X-Bricks to 4 X-Bricks.
Third expansion: From 4 X-Bricks to 8 X-Bricks.
This sequence ensures that the storage array scales properly, maintaining performance and redundancy.