Disk Monitor

Your typical magnetic platter hard drive is comprised of a system of moving parts, meaning in time it will fail: eventually. In most cases, there are indications that a drive is about to fail... noises, grinding, and so on. But even before a disk gets to this stage, it is possible to track the media errors and predictive failures on the drive via SMART. To do this on an ongoing basis, we employ a SMART daemon.

$ sudo emerge -av smartmontools

Once the packages are installed, set the following in the configuration file:
File: /etc/smartd.conf

DEVICESCAN -a -o on -S on -n standby,q -s (S/../.././02|L/../../6/03) -W 4,35,40 -m address@domain.ext

This will scan all of the drives in your system on an ongoing basis, and send an email alert if one of the drives fails the basic test. Obviously, replace the email address in the example above with your own.

As per the regular Gentoo hierarchy, configure the service to start with the system

$ sudo rc-update add smartd default

And start the service

$ sudo /etc/init.d/smartd start