This plugin does SMART monitoring both ATA and SCSI disks, has an easy usage
syntax, and automatically produces perfdata for all applicable metrics.

Note:
On older distributions you need a line like
nagios ALL=NOPASSWD: /usr/sbin/smartctl
in /etc/sudoers to run this script as non privileged user.

Since SLES 12/openSUSE 12.1, there is a file
%{_sysconfdir}/sysconfig/sudoers.d/%{name}
which holds the same content and should be used automatically.