DiskScan is a tool to scan a block device and check if there are unreadable
sectors, in addition it uses read latency times as an assessment for a near
failure as sectors that are problematic to read usually entail many retries.

Diskscan will only perform reads in its disk surface scan so it is not
destructive in any way and it will report on all the key metrics needed to
decide if the disk is good or not.

 
