I have numerous hard drives and i figure i should benchmark them every so often because that's what websites tell me to do. But i'm worried if using the stock "Disks" utility that comes with Ubuntu 16.04 desktop will affect any data already on the drives. There is only one option "Start Benchmark", so it's not like i have any useful information to work from.
I suppose it's a multi-pronged question:
Is it safe to benchmark a drive with stuff already on it? If so, is it also safe if that drive is being accessed by the system for whatever reason, or should i make sure nothing else is accessing that drive first? should i dismount them first (and i suppose, can i benchtest an unmounted drive?), and finally, do i really need to do these every month or so as some sites are suggesting; they aren't as trustworthy (to me) as askubuntu, and i've always valued the opinion of the people in this group.