Alessandro Dotti Contra

Linux/Unix DevOps


Minimal SMART reference

I gather this notes some times ago from a website I didn't have the wit to bookmark. Since from time to time I need these information, I decided to put them here.

Remeber that if a parameter gets lower than its threshold, it's time to take action.

Critical device status attributes

Reallocated sectors: number of defective sectors remapped using a spare sectors pool.

Current pending sectors: number of suspected defective sectors. These sectors will be tested again by device off-line scan.

Off-line uncorrectable sectors: number of defective sectors found during the off-line scan.

Read error, Read error retry, Write error, Seek error rates: rates at which specified errors occur.

Recalibration retries: how often the drive is unable to recalibrate at the first attempt.

Spin up time: the time the drive takes to spin up to its reated speed. Might indicate either a controller or a spindle bearing problem.

Spin retry: count the times the drive was unable to spin its platters in due time. Might indicate severe controller or bearing problems or, sometimes, power supply problems.

Drive lifetime information

Drive start/stop, Power off/retract cycle counts: provide the estimation of the drive wear (when compared to vendor estimated values).

Power on hours / Head flying hours counts: the time of hard disk activity.

Media Wearout Indicator / SSD_Life_Left: for SSD drives, reports the life left (in percentage). Vendor specific, may have different names.

Operating conditions information

Temperature: the device temperature.

Ultra DMA CRC error rate: typically indicates that something is wrong with the connectors and/or cables.

G-sense error rate: indicates if the errors are occurring due to the drive shocking.