A Check_MK plugin which is supplied as part of the standard install but not 'turned on' is the 'smart' agent. It is a plugin which resides on the target with hard-drives to be monitored. Temperatures and other useful statistics can be collected.
The plugin can be found in the share/check_mk/agents/plugins/ directory amongst a number of other useful plugins.
It needs to be copied to the /usr/lib/check_mk_agent/plugins/ directory on the target to be monitored.
In order to be useful, the 'smartmontools' package needs to be installed as a pre-requisite.
On one of my systems, I get output some output similar to:
SMART WDC_WD1003FZEX-00K3CA0_WD-WCC6Y3PN9XKC Stats OK - Powered on: 3529 hours, Power cycles: 51, Reallocated sectors: 0, Reallocated events: 0 (was 0 during discovery: normalized value looks OK), Spin retries: 0, Pending sectors: 0, UDMA CRC errors: 0 Temperature SMART WDC_WD1003FZEX-00K3CA0_WD-WCC6Y3PN9XKC OK - 30 °C
Values are charted as well.