If the media is unreliable - then it adds additional codes of the Hamming type to restore the damaged bits after a crash. 99% of normal carriers is implemented in hardware. If your flash drive fails or is not very reliable then it is advisable to buy a new one. If you still want to nakovyryat gold in the muck, look in the direction of the par2 utility manpages.org/par2
she to ten percent will increase the size of your backups but will guarantee fixing a few bits if that will. It runs over a file system and its control codes are just additional files side by side.
And check whether backup vosstanovit in principle - impossible. As in that of philosophical thought - it is impossible to know what the pudding until you have eaten. Therefore, to guarantee integrity the backup at the logical level is possible only after the simulation of a full recovery in DB.