From LedHed's Wiki
Contents
Useful smartctl commands
View SMART test results
smartctl -l selftest /dev/da0
View SMART data
smartctl -A /dev/da0
View Disk Info
smartctl -i /dev/da0
Health Assessment
smartctl -H /dev/da0
Perform SMART Test on drive
smartctl -t short /dev/da0
or
smartctl -t long /dev/da0
Note: that the long test can take quite a bit of time.
Cancel a running test
smartctl /X /dev/da0
Check testing times
smartctl -c /dev/da0
This will display the approximate times it takes to perform various SMART tests.