Whether you’re using FreeBSD for your workstation, a simple home server, or in a complex IT environment where reliability is critical, losing the data on your hard disk(s) is probably the worst type of failure you can have. I’ve already gone over a backup strategy for FreeBSD, but it’s best to try to prevent data loss before it happens.
As it turns out, pretty much all modern hard disks have built-in SMART technology (SMART stands for Self-Monitoring, Analysis and Reporting Technology). It can alert you before many types of problems will occur, and hopefully provide you with enough time to get your data off the drive safely, before catastrophic failure occurs.
It’s pretty easy to take advantage of this technology on FreeBSD with a package called Smartmontools.