Failed to launch. Local synchronization is needed - between two datastores inside one pbs - the old array and the new iscsi mounted to it.You can use the sync feature https://pbs.proxmox.com/docs/managing-remotes.html
I mounted pbs as a remote to myself. Synchronization has started. After its completion - change the place of copying copies and you can delete the old datastore and remove the remote or do you need something else?You first have to add the local datastore as remote.
I do not recommend copying, although, if done right, it should work. Please first try using the sync.
I didn't quite put it exactly - I meant to change the old datastore to a new one in the backup tasksI'm sorry, I don't quite get what you mean with "change the place of copying copies". You can delete the old datastore after having synced all the backups, yes.