checking bad sector
But did you know that..
While using mke2fs or mkfs.ext4 to create a file system. It is always recommended to use -c option. It will check and make sure that there are no bad blocks on the device.
mke2fs -c /dev/sda8
This will do a read only test on the file system. Specifying -c -c (i.e. -c two times) will perform a read-write test and will be slower than -c.