lubuntu@lubuntu:~$ sudo badblocks -vsn /dev/sda 
Checking for bad blocks in non-destructive read-write mode
From block 0 to 12714911
Checking for bad blocks (non-destructive read-write test)
Testing with random pattern: 9445740 done, 1:51:51 elapsed. (0/0/0 errors)
9445741 done, 1:51:55 elapsed. (1/0/0 errors)
9445742 done, 1:51:59 elapsed. (2/0/0 errors)
9445743 done, 1:52:06 elapsed. (3/0/0 errors)
done                                                 
Pass completed, 4 bad blocks found. (4/0/0 errors)
lubuntu@lubuntu:~$