dd if=/dev/urandom of=/myfile.bin bs=1M count=3
hdparm --fibmap /myfile.bin
hdparm --read-sector xxxxxx /dev/sdb
rm /myfile.bin
sync
hdparm --read-sector xxxxxx /dev/sdb
dd if=/dev/urandom of=/myfile.bin bs=1M count=3 hdparm --fibmap /myfile.bin hdparm --read-sector xxxxxx /dev/sdb rm /myfile.bin sync hdparm --read-sector xxxxxx /dev/sdb