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by feelix 3475 days ago
In practice, although HDD's are meant to be able to deal with bad blocks, and remap them, I have found the opposite to be true.

(I've been working at a low level with disks for over a decade, writing data recovery apps and such)

I have found in practice that by the time a HDD develops a single bad block, 99% of the time it's on a death spiral and it's going to completely die within a month or two.

It seems like none of this bad block remapping, spare space, or anything of the sort has any effect whatsoever. The only thing that keeps them alive is being well enough engineered not to break at all.

Please correct me if my experienced misinformed me and I'm wrong.

1 comments

In the past, a utility did the determination and remapping via off-disk software.

My understanding was the traditional "bad block" behavior was actually hidden - there are bad blocks that occur but the firmware silently remaps everything.

When you see a bad block at the level you can see via e.g. smartctl program, that means the space set aside for bad block remapping is full - the drive has already been silently failing for a while now.