Ah, sorry. Somehow I missed the part where you wrote the block...:-)
No answers from me in that case. I'm as eager as you, to know the response.

On Jul 11, 2013 10:18 AM, <robert@spotswood-computer.net> wrote:
I did the read (hdparm --read-sector), it failed, so I wrote to the block.
I agree this should force the reallocation/re-mapping. But according to
smart, it didn't. The reallocation count remained at 0. That's the part
that doesn't make sense. Shouldn't the reallocation/re-mapping increase
the count???

BTW, I just (about 5 minutes ago) had an identical experience with
different HD. I unreadable [pending] sector. Wrote to it and the
reallocation is still 0.

In both cases, these were drives I was planning on reformatting anyway, so
I took the opportunity to experiment...

> Here's how I understand things [which could easily be wrong] - a failed
> *read* won't get a bad/failing block re-mapped to a "good" block - only
> failed *writes.*
>
> You might have a read that fails only part of the time - so occasionlly it
> will read properly and all will be well.
>
> To force a re-map of the bad block, you'll need to try to write to that
> block. If the write fails, then it will re-map the block to one of the
> spares.
> Before writing to the block, you may want to try to read it and/or verify
> there's nothing there you actually need.
>
> HTH
> -Greg
>
>
>
> On Thu, Jul 11, 2013 at 9:38 AM, <robert@spotswood-computer.net> wrote:
>
>> I had a hard drive yesterday I ran smarttools on. It showed one current
>> pending sector count. I ran a short test and it failed on a specific
>> block
>> at 10%. From what I read here, that's not uncommon for a hard drive to
>> stop the test at the first bad block it finds. Looking through the
>> extended error log (smartctl -x /dev/sda) - the regular error log was
>> empty - I found a bunch of errors. All the complete error reports
>> pointed
>> to the same specific block.
>>
>> To verify, I tried hdparm --read-sector <number of sector found above>
>> and
>> it failed. Since I had nothing to loose, I wanted to see if I could
>> change
>> the pending count, so I used hdparm --write-sector <number of sector
>> found
>> above> --yes-i-know-what-i-am-doing /dev/sda. This worked.
>>
>> Now I used hdparm to try to read that block/sector again and I could,
>> although it had no data. Not surprising. I figured I had just forced the
>> firmware of the drive to reallocate a spare block, so the pending count
>> would go to 0, and the reallocated count would be 1.
>>
>> But when I ran smartctl -x /dev/sda again, the reallocated sector count
>> was still 0! The pending count was also 0 as was the Reallocation Event
>> Count and the Offline Uncorrectable. I re-ran the short test, and this
>> time it passed. I even ran badblocks on the whole drive, and no bad
>> blocks
>> were found.
>>
>> Can someone explain what I did/saw? I find it hard to believe I
>> "repaired"
>> the bad sector, but that's the only explanation I can come up with to
>> explain my results.
>>
>>
>>
>>
>>
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