Bad Sectors: Logical vs Physical and the Imaging Order
A bad sector is a symptom. Whether it is logical (content) or physical (media) changes the whole strategy.
Telling them apart
Physical sectors fail consistently and cluster; logical ones read fine after a rewrite but indicate instability. SMART reallocation counts and read-speed maps separate the two.
Imaging order
Image healthy regions first, skip error zones with tracking, then retry failing areas at lower speed and multiple passes. Every full-surface scan on a weak drive costs life.
FAQ
Should I run a surface test?
No. It reads everything and accelerates failure; image instead.
Can bad sectors be 'repaired'?
Only remapped. The data in them is usually lost.