This can be done individually for each instance.
First make sure the new backup location has the same ownership as the instance (such as the
amp user on Linux). You should also have separate backup locations for each instance (subdirectories are fine), so that backups don’t mix.
LocalFileBackupPlugin.kvp in the instance’s datastore, and change the location in
Storage.StorePath= so that it points to the full path of the new backup location (ending in
Finally, restart the instance.