In addition to Alex's advise, some info around 'vol move'.
Please note: In ONTAP 8.3 & 9.x, "Automatic throttling" occurs during the initial baseline phase to assure that the workload imposed by the vol move does not adversely affect "end-user latency and throughput". The throttling automatically adjusts itself as client or host traffic increases and decreases, effectively deprioritizing vol move in favor of end-user applications. Throttling may also take effect while certain scanners, such as those for storage efficiency, are running.
Therefore, timing of the vol_move is key here (as you would be more aware of the Node's resource demand, OCUM is a good tool that can suggest how resources are being used). Also, while the vol_move is in progress, it goes through different phases, and it reports the progress in each phase. Vol move show command is handy, as it will report for example:
Example: (output of vol move show)
a) Move Phase: replicating
b) Estimated Remaining Duration: 00:00:07.000
c) Replication Throughput: 157.6MB/s
d) Duration of Move: 00:00:42.000
Related:
https://docs.netapp.com/us-en/ontap-sm-classic/volume-move/task_planning_method_timing_volume_move.html
https://kb.netapp.com/Advice_and_Troubleshooting/Data_Storage_Software/ONTAP_OS/How_many_vol_move_operations_can_be_active_at_the_same_time
https://kb.netapp.com/Advice_and_Troubleshooting/Data_Storage_Software/ONTAP_OS/Volume_move_too_slow_or_not_working