Inspect and run SMART checks from the shell to spot failing disks before data loss. 17.12.2025 | reading time: 2 min On Linux, `smartctl` from smartmontools lets a user read SMART data and run self-tests to detect failing drives early; a quick check can save hours of recovery work and avoid surprises. Quick health probe Do this: run the overall-health check and inspect full attributes; example: ``` sudo smartctl -H /dev/sda === START OF READ SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED `````` sudo smartctl -a /dev/sda === START OF READ SMART DATA SECTION === ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 5 Reallocated_Sector_Ct 0x0033 100 100 036 Pre-fail Always - 0 197 Current_Pending_Sector 0x0012 99 99 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0010 100 100 000 Old_age Offline - 0 ``` Start and check a self-test Run a short self-test and then review results; example: ``` sudo smartctl -t short /dev/sda smartctl 7.2 2020-12-30 r5155 [x86_64-linux-5.11.0-37-generic] (local build) Please wait 2 minutes for test to complete. `````` sudo smartctl -l selftest /dev/sda SMART Self-test log structure revision number 1 Num Test_Description Status Remaining Lifttime(hours) LBA_of_first_error # 1 Short offline Completed without error 00% 1234 - ``` What to watch in attributes Look for rising RAW values in Reallocated_Sector_Ct, any non-zero Current_Pending_Sector or Offline_Uncorrectable, and a failing overall-health result; vendor names vary, so compare VALUE to THRESH and watch trends rather than single readings. Automate and extend monitoring Use `smartd` to schedule tests and email alerts, check SSD wear-leveling attributes for endurance, and prefer `nvme-cli` for deep NVMe telemetry when available; run checks from rescue media if a system won't boot. Final note SMART is not perfect but it is a practical, low-effort early warning system; add regular checks to your maintenance routine and consider formal Linux certification to deepen system knowledge with bitsandbytes.academy exam preparation for CompTIA Linux+ or LPIC-1. Join Bits & Bytes Academy First class LINUX exam preparation. storage utilities troubleshooting
