What is the correct order in which the XtremlO X1 cluster components should be powered...

The correct order in which the XtremIO X1 cluster components should be powered on for the first time is:

PDU (Power Distribution Unit)

BBUs (Battery Backup Units)

XMS (XtremIO Management Server)

Storage Controllers

Detailed Explanation with References:

PDU (Power Distribution Unit): Begin by powering on the PDU to provide power to the entire rack.

BBUs (Battery Backup Units): Next, power on the BBUs to ensure power protection for the system.

XMS (XtremIO Management Server): Power up the XMS to allow management and monitoring of the storage system.

Storage Controllers: Finally, power on the Storage Controllers to bring the storage system online.