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I heard that if we format HDD with "Zero Out Data" option, then it also takes care of bad sectors and marks them and re-maps them to other blocks. Is it true?

If it is then 7-Pass or 35-Pass would do the same (bad sectors fix) and with high assurance?

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up vote 1 down vote accepted

Zero Out Data is enough. It is highly unlikely that any marginal blocks will be missed, so extra passes are a waste of time as far as locking out blocks goes. The 35-pass erase overkill froISA security perspective as well, since it is based on what amounts to an urban legend about how to securely erase any of the ancient obsolete styles of hard drives from the 1980's.

Beware that any drive that has detected bad blocks is probably circling the drain already. Don't trust it for anything.

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