Example: Switchable expansion unit
In this example, there is a figure that shows a cluster consisting of four nodes.
Nodes named A, B, and C are defined to be in the same device domain. There are two switchable expansion units - one contains IASP33 and the other contains IASP34 and IASP35. The expansion unit containing IASP33 is on an HSL loop that also contains nodes A and B. This first expansion unit can be switched between nodes A and B. The expansion unit containing IASP34 and IASP35 can be on another HSL loop that also contains nodes B and C. This second expansion unit can be switched between nodes B and C. Node D is contained in the cluster, but is not a member of the device domain and therefore can only access IASP36, a stand-alone (or dedicated) independent disk pool.