Like the others said, it forced the drive to rewrite the track containing the bad sector, at which time the drive itself either repairs the bad bits or remaps the sector/track to a factory "spare" designated for such purposes.

Sometimes writing only the reported bad sector won't work -- as in the first attempt here. The reason for that is that drives don't actually work on a per-sector basis anymore, and so writing the entire "track" is required to "fix" it. But nobody other than the drive itself knows what a "track" is, so the second command I gave you simply nukes the entire partition, hoping that this will include enough of the physical "track" to get the job done.

In the course of this, you will have lost your radio presets, equalizer settings, and per-track sound profiling data that the player automatically builds up. All of that stuff was on /dev/hda3 somewhere. No biggie, but a minor nuisance for some.

Cheers