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Running S.M.A.R.T. Tests

  3 minute read.

Last Modified 2022-05-31 14:38 EDT

S.M.A.R.T. (Self-Monitoring, Analysis and Reporting Technology) is an industry standard for disk monitoring and testing. Disks can be monitored for problems using several different kinds of self-tests. TrueNAS can adjust when and how alerts for S.M.A.R.T. are issued. When S.M.A.R.T. monitoring reports an issue, we recommend you replace that disk. Most modern ATA, IDE, and SCSI-3 hard drives support S.M.A.R.T. Refer to your respective drive documentation for confirmation.

S.M.A.R.T. tests are run on a disk. Running tests can reduce drive performance, so we recommend scheduling tests when the system is in a low-usage state. Avoid scheduling disk-intensive tests at the same time! For example, S.M.A.R.T. tests should not be scheduled on the same day as a disk scrub or resilver.

Go to Storage > Disks and click to expand an entry. Enable S.M.A.R.T. shows as true or false.

To enable or disable testing, click EDIT DISK(S) and find the Enable S.M.A.R.T. option.

Manual S.M.A.R.T. Tests

To quickly test a disk for errors, go to Storage > Disks and select the disks to be tested. After selecting the desired disks, click MANUAL TEST.

StorageDisksManualTest Options

Next, select the test Type. Each test type can be slightly different based on the drive connection, ATA or SCSI:

ATA Connection

  • Long - runs SMART Extended Self Test. This scans the entire disk surface and can take many hours on large-volume disks.
  • Short - runs SMART Short Self Test (usually under ten minutes). These are basic disk tests that vary by manufacturer.
  • Conveyance - runs a SMART Conveyance Self Test. This self-test routine is intended to identify damage incurred during transporting of the device. This self-test routine requires only minutes to complete.
  • Offline - runs SMART Immediate Offline Test. The effects of this test are visible only in that it updates the SMART Attribute values, and if the test finds errors, they appear in the SMART error log.

SCSI Connection

  • Long - runs the “Background long” self-test.
  • Short - runs the “Background short” self-test.
  • Offline - runs the default self test in foreground. No entry is placed in the self test log.

For more information, refer to smartctl(8).

Click START to begin the test. Depending on the test type you choose, the test can take some time to complete. TrueNAS generates alerts when tests discover issues.

Go to Storage > Disks, expand an entry, and click S.M.A.R.T. TEST RESULTS. From the Shell, use smartctl and the name of the drive: smartctl -l selftest /dev/ada0.

Automatic S.M.A.R.T. Tests

Go to Tasks > S.M.A.R.T. Tests and click ADD.


Choose the Disks to test, Type of test to run, and Schedule for the task.

S.M.A.R.T. tests can offline disks! Avoid scheduling S.M.A.R.T. tests simultaneously with scrub or resilver operations.

Saved schedules appear in the Tasks > S.M.A.R.T. Tests list.

To verify the schedule is saved, you can open the shell and enter smartd -q showtests.

Service Options

You must enable S.M.A.R.T. service to run automatic S.M.A.R.T. tests.

Disable the S.M.A.R.T. service when disks are controlled by a RAID controller. The controller monitors S.M.A.R.T. separately and marks disks as a Predictive Failure on a test failure.