But the email alert system is very proactive about sending out mails with disk warnings.
2 weeks ago, one of my disks failed, and I only noticed because I started getting emails from rockstor about problems writing to / reading from that particular disk. The pool was still accessible (although slow in performance) at the point where I started getting messages.
I also have a couple of disks that have had CRC errors on the SATA channel. And Rockstor sends me a mail every time I check the SMART status for these drives (even though the errors are several months old, and was down to defective cables). But Its reassuring that you get these warnings.
So I would suggest setting up e-mail alerts as a first measure.