In the olden days you used to have to take a note of the badblocks that were written on the drive and enter those in the defect list before formatting the drive, because hard disk surfaces were never "perfect", manufacturer's got wise to this because people buying disks would look at the defect table printed on the disk and buy the ones with the least amount of defects...
Now scroll forward 20 or so years and hard disk manufacturers hide the fact a brand new disk has bad blocks with the firmware, when you buy a brand new disk it will have in all probability bad blocks already, the firmware will detect newly grown badblocks and maps them out from a set of spare cylinders it has, but this only happens when a write operation occurs on that sector and the ECC algorithm detects bit failure, only then will it map the block out. So getting back to the point you can force a drive to map out the badblocks by simply using DD, ie/ [edit: following example was edited to prevent accidental drive destruction: removed wildcard character, replaced with X]
dd if=/dev/zero of=/dev/sdX bs=1M
obviously alter the of=target to reflect the drive you want to zero
this is the quickest way to re-map a drives defects, its also the quickest way to totally trash your Linux setup by getting the target drive wrong, so check, double check then check again, before you press the enter key. You can increase the size of the blocksize in the dd command to optimize read/writes and perhaps make things go quicker, but there are diminishing returns after a point. I find anything between 1M and 8M works best for me
You can get DD to just write one sector, the bad one... to get it remapped, so you don't have to backup your drive, but that's a whole different kettle of fish and Russian roulette if you don't know exactly what you're doing .....
This command WILL destroy everything on your hard drive including any partitions. But it will force the drive to map out any bad sectors it may have.
It is perfectly ok for a disk to have bad sectors as long as they aren't on the boot sector, if they are then the drive is useless, if you notice a few months later that your drive has developed more bad sectors then it's time to start shopping for a replacement.
I've revived hundreds of drives like this and they've lived on for many years afterwards, a bad sector isn't necessarily the death knell for the drive.