fnord@vgnnr498e:~$ sudo smartctl -t long /dev/sda
smartctl 6.5 2016-01-24 r4214 [x86_64-linux-4.4.0-47-generic] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF OFFLINE IMMEDIATE AND SELF-TEST SECTION ===
Sending command: "Execute SMART Extended self-test routine immediately in off-line mode".
Drive command "Execute SMART Extended self-test routine immediately in off-line mode" successful.
Testing has begun.
Please wait 119 minutes for test to complete.
Test will complete after Fri Nov 25 17:50:31 2016

Use smartctl -X to abort test.
fnord@vgnnr498e:~$