Customer has deployed VDI through MCS on HPE SimpliVity, If he tried to add new VDI to a existing Machine Catalog, the storage of new VDI is not load balanced. if he tried to MCS new VDI, the storage of new VDI is load balanced.
for example, there are 5 nodes in HPE SimpliVity, in abnormal scenario, the new VDI did not select storage on "Node 5".
As described in https://damianerangey.wordpress.com/2018/08/29/how-virtual-machine-data-is-stored-and-managed-within-a-hpe-simplivity-cluster-part-2/. VDI desktops are deployed, linked clones are created on random hosts. Linked clones mostly read from the read only templates and write locally which causes proxying and adds extra load to the nodes that host the read only templates.
This is the design of HPE SimpliVity, HPE provided a algorithm of selecting storage in the back ground, it is out of Citrix control.
CVAD - Storage allocation does not load balance during MCS operation in HPE SimpliVity
https://builddaylive.com/hpe-simplivity/how-vm-data-is-managed-within-an-hpe-simplivity-cluster-part-4-automatic-capacity-management/
https://builddaylive.com/hpe-simplivity/how-vm-data-is-managed-within-hpe-simplivity-clusters-part-5-analyzing-cluster-utilization/