This plugin does SMART monitoring both ATA and SCSI disks, has an easy usage
syntax, and automatically produces perfdata for all applicable metrics.
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
which holds the same content and should be used automatically.