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Bad Sectors Disappeared

November 24th, 2011, 16:22

I have a Maxtor hard drive that had 6 bad sectors on it yesterday before benchmarking in HDTune. I started the benchmark but it didn't finish because of a read error. HDTune showed over 200 bad sectors and an Error Scan showed many red Damaged blocks. I then did a low level format with Maxtor's tool. Now HDTune shows 6 bad sectors, the benchmark completes fine, and the Error Scan shows no bad blocks. Where did the 200 bad sectors go?

Re: Bad Sectors Disappeared

November 24th, 2011, 17:53

I have an idea what you might mean, but you're using ambiguous terms and you haven't supplied any screenshots or other data, to help explain what you mean by terms like "bad sectors".

What data do you have showing "6 bad sectors"?

What data do you have showing "over 200 bad sectors"?

If neither of those 2 bits of evidence is a current, full, SMART output from the drive, please collect & supply that.

Depending on exactly what you (and HDTune) means by "bad sectors", then the "low level format" you did, will have caused any "pending reallocation" sectors to be tested and, if needed, to be reallocated. That is going to be part of your answer, but as yet, without more explanation & evidence from you, I don't fully understand your question :-)

With full, clear answers to the above, you may get further replies.

Re: Bad Sectors Disappeared

November 24th, 2011, 19:37

Thanks for the reply. Sorry I wasn't clear.

>>> What data do you have showing "6 bad sectors"?

From HDTune's Health tab: Reallocated Sector Count

>>> What data do you have showing "over 200 bad sectors"?

Same place: HDTune's Health tab: Reallocated Sector Count

>>> Depending on exactly what you (and HDTune) means by "bad sectors", then the "low level format" you did, will have caused any "pending reallocation" sectors to be tested and, if needed, to be reallocated.

If they were reallocated, why don't I see them in the Reallocated Sector Count? Can bad sectors become "unreallocated"? If they're not bad, why did HDTune show all the red Damaged blocks before and not now?

Re: Bad Sectors Disappeared

November 25th, 2011, 15:34

Thanks for the info, although you didn't include the raw SMART output which I requested.

Based on what you say you did, and since I don't see detailed public info on exactly what vendor-specific behaviour that Maxtor utility has, I expect that utility effectively moved the G-list into the P-list - thereby preventing those sectors from being seen the "Reallocated Sector" count (which is the number of sectors in the G-list).

Unfortunately you would have needed to read the P-list (which requires proprietary commands) before running the Maxtor LLF utility, to allow for comparison with the P-list now (i.e. is it 200 sectors larger now?) and to prove / disprove this theory. However, if your drive is creating that many bad sectors, then either it is starting to fail, or you have another problem e.g. power supply issues.
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