Originally Posted by ust
it can be used to check badsector ? if not , what command / tools can use to check ?
Are you sure its bad sectors you want to check, rather than bad blocks? You may have to so called "low-level" format to update the drives' bad sector table. Download the drive manufacturer's software tools to do this. It will test each sector with a read and write, so it is destructive - you need to backup your data first.