On Wed, Sep 09, 2020 at 04:53:49PM +1000, Brad Campbell via Dng wrote:

>
> A drive will absolutely not re-allocate a sector until it is written to.
> Then it will first try and re-write the sector in case the error is due to
> something like a power loss or other transient. Failing a good write it'll
> then reallocate and write the data to another (transparent) location.

Let me wonder how the drive knows a sector is bad when it writes to it.
Does it read it back as a check?

-- hendrik