S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) is a supplementary component build into many modern storage devices through which devices monitor, store, and analyze the health of their operation. Statistics are collected (temperature, number of reallocated sectors, seek errors...) which software can use to measure the health of a device, predict possible device failure, and provide notifications on unsafe values.
The smartmontools package contains two utility programs (
smartd) to analyze and monitor storage devices. Install from the official repositories.
Detect if device has SMART support
To check if the device has SMART capability (it may be necessary to add
-d ata to specify it is an ATA derived device):
# smartctl -i /dev/<device>
(where <device> is
sda, hda,...). This will give general information about the device, the last two lines will show if it is supported:
SMART support is: Available - device has SMART capability. SMART support is: Enabled
If SMART is not enabled, it can be enabled by doing:
# smartctl -s on /dev/<device>
Test the device health
Three type of health tests that can be performed on the device (all are safe to user data):
- Short (runs tests that have a high probability of detecting device problems)
- Extended (or Long; a short check with complete disk surface examination)
- Conveyance (identifies if damage incurred during transportation of the device)
To view the device's available tests and the time it will take to perform each test do:
# smartctl -c /dev/<device>
To run the tests do:
# smartctl -t short /dev/<device> # smartctl -t long /dev/<device> # smartctl -t conveyance /dev/<device>
To view the test's overall health status (compiled from all tests):
# smartctl -H /dev/<device>
To view the test's result errors:
# smartctl -l selftest /dev/<device>
To view the test's detailed results:
# smartctl -a /dev/<device>
If no errors are reported the device is likely healthy. If there are a few errors this may or may not indicate a problem and should be investigated further. When a device starts to fail it is recommended to backup the data and replace it.
Devices can be monitored in the background with use of the smartmontools daemon that will check devices periodically and optionally email any potential problems. To have devices monitored on boot, enable smartd service:
systemctl enable smartd.service
The smart daemon can be edited for more exact configuration in
/etc/smartd.conf (the configuration is well commented) otherwise all tests are run on all devices. Or, each device can be specified and all tests run by doing (uuid's and device ID can be used for more exact matching):
#DEVICESCAN /dev/<device> -a
Other options include:
-n standby,qto run diagnostics only when device is spun-up.
- Details about smartd operations can be found in:
Email potential problems
To have an email sent when a failure or new error occurs, use the
DEVICESCAN -m email@example.com
To be able to send the email externally (i.e. not to the root mail account) a MTA (Mail Transport Agent) or a MUA (Mail User Agent) will need to be installed and configured. Common MTAs are MSMTP and SSMTP. Common MTUs are sendmail and Postfix. It's enough to simply configure S-nail if you don't want anything else.
Once the mail agent is setup the
-M test option can be used to test if an email will be sent (restart the daemon immediately to discover):
DEVICESCAN -m firstname.lastname@example.org -M test
If you use a computer under control of power management, you should instruct smartd how to handle disks in low power mode. Usually, in response to SMART commands issued by smartd, the disk platters are spun up. So if this option is not used, then a disk which is in a low-power mode may be spun up and put into a higher-power mode when it is periodically polled by smartd.
DEVICESCAN -n standby,15,q
More info on smartmontools wiki.
- Gsmartcontrol — A GNOME frontend for the smartctl hard disk drive health inspection tool