Уж послали, так послали

root@raid-sata-hdd:~# smartctl -t offline /dev/sda

=== START OF OFFLINE IMMEDIATE AND SELF-TEST SECTION ===
Sending command: "Execute SMART off-line routine immediately in off-line mode".
Drive command "Execute SMART off-line routine immediately in off-line mode" successful.
Testing has begun.
Please wait 22036 seconds for test to complete.
Test will complete after Tue Mar  2 20:20:05 2021 CET
Use smartctl -X to abort test.

22 тысячи секунд - это 6 дней, если что.