Test harddisk for bad blocks

# badblocks -e 10 -s -w /dev/mmcblk0 
 -e max bad block count 
Specify a maximum number of bad blocks before aborting the test. The
default is 0, meaning the test will continue until the end of the test
range is reached. 
 -s show progress 
 -w use write mode 
 -n Use non-destructive read-write mode. 
By default only a non-destructive read-only test is done. This option
must not be combined with the -w option, as they are mutually
exclusive. 
 Pass completed, X bad blocks found (R/W/C errors) 
 The three numbers in the parentheses correspond to: 
 
 Read errors: Errors encountered while reading from the disk. 
 Write errors: Errors encountered while writing to the disk. 
 Corruption (Compare) errors: Errors where the data read back from
the disk does not match what was written (i.e., data corruption detected
during verification) 
 
 # smartctl -t long /dev/device 
 remember no smart on sd cards