Ok.
As far as vol reaper is concerned, you can check the current status, to check if there is anything pending in the queue. There is a default retention time, so once that is passed, it will be re-attempted, I think these are scheduled internal jobs of ONTAP. However, open a ticket to support, to be 100% sure. It will not stop you from upgrade, as we understood.
Coming to NDMP reaper context: That suggests, there are backups in your environment involving NDMP Protocol? Is that correct ? I found this kb, that explains the reason. Please check which version of ONTAP you are running, in the bug-report.
https://kb.netapp.com/onprem/ontap/os/The_upgrade_aborted_on_task_%22NDMP_rbe_context_reaper_9.8_Upgrade_Revert_Task%22
https://mysupport.netapp.com/site/bugs-online/product/ONTAP/BURT/1386268
If your ONTAP is among the Fixed In Versions, then no action needed.
Basically, NDMP 4.0 (extensions) has restartable_context feature, that allows NDMP backups to be restared from the check_point, however, it's the job of the DMA to delete the context for the given job that has completed successfully. Sometime, DMA fails to delete the context, and they keep accumulating, until it is unsafe for the upgrade.
You can check the queue:
::> vserver services ndmp restartable-backup show
false: the context has not been deleted by the backup application
true: the context is in progress to be deleted by the backup application
Delete restartable contexts:
https://docs.netapp.com/us-en/ontap/tape-backup/delete-restartable-contexts-task.html
Best advise: reach out to NetApp support, so that they can also review your query and you could refer the support ticket, in case you bump into any issue during upgrade.
