A customer will need to perform an upgrade from 9.

Aggregate relocation enables nondisruptive hardware maintenance during an ONTAP upgrade or controller maintenance activity. ARL moves aggregate ownership between HA partners so that storage resources remain available while a node is serviced or upgraded. FlexVol and FlexGroup are volume types and do not provide the controller-level maintenance mechanism required in the scenario. RAID-TEC protects against multiple disk failures, but it does not move aggregates away from a controller for nondisruptive maintenance. The key support concept is that ONTAP nondisruptive operations rely on HA takeover/giveback and aggregate relocation to keep data online while hardware or software work occurs. For an upgrade from an older release to a later release, ARL is central when the process requires controller reboot or hardware service without forcing client downtime. This is why ARL is repeatedly tested in support exams: it is the operational bridge between hardware service and continuous data availability. References/topics: ONTAP nondisruptive upgrade, aggregate relocation, HA pair maintenance, controller availability, and upgrade readiness.