Fixing a bad logical HDD sector...

  • Thread starter Thread starter Eric
  • Start date Start date
E

Eric

Hi,

I just picked up a couple new drives and wanting to copy an entire partition
over to a new drive but have one bad logical sector that is causing the copy
to error out. This is a WinXP partition. This is not a bad physical
sector, but rather a "bad" logical sector. The HDD is not damaged. "Bad"
logical sectors result when the CRC value of a sector differ from the data
within, most likely a result from an inadvertent power cycle. If the HDD
were to be simply reformated, the "bad" logical sector would be removed. In
the DOS days, I remember getting some of these "bad" logical sectors every
now and then and would just copy the actual file that resides over the
sector elsewhere and then copy it back. That would "clear it out".

Again, this HDD is not physically damaged. I tested the drive with the
manufacturer's Drive Fitnest Test, Spinrite, S.M.A.R.T., and HDD Regen.
There are no physical problems. In fact, if it were a physically bad sector
then that would be a good thing -- as the drive would've just remapped that
sector to a reserve sector and I'd be able to copy with no problems.
Diagnostic software all reported there are plenty of reserve sectors
available.

I ran chkdsk, from the recovery console as well. "Chkdsk /f" and "chkdsk
/r". The only thing chkdsk finds is one crosslinked file, which seems to
be located at exactly where this "bad" logical sector is. In DOS/Win9x,
chkdsk always gave the name of the actual crosslinked file but with NTFS
(WinXP), it is giving a file number. Is there a way to determine the actual
file from the file number it is giving? I'm pretty confident that if this
particular file was just copied, deleted, re-copied it would clear up this
"bad" logical sector.

Thanks,
-Eric
 
I just picked up a couple new drives
Click to expand...

This shouldnt be happening with a new drive.
and wanting to copy an entire partition over to a new
drive but have one bad logical sector that is causing
the copy to error out. This is a WinXP partition. This is
not a bad physical sector, but rather a "bad" logical sector.
Click to expand...

Nothing 'logical' about it, its a physical sector.
The HDD is not damaged. "Bad" logical sectors result
when the CRC value of a sector differ from the data within,
most likely a result from an inadvertent power cycle.
Click to expand...

Statistically that is very unlikely to have happened
with a new drive and most modern drives dont
produce a bad sector when that happens either.
If the HDD were to be simply reformated,
the "bad" logical sector would be removed.
Click to expand...

Utterly mangled all over again. If by 'logical sector'
you actually mean a cluster at the OS level, a format
wont necessarily get rid of that if the physical sector
is bad, it will be retained thru a format at the OS level.
In the DOS days, I remember getting some of
Click to expand...
these "bad" logical sectors every now and then

That shouldnt have happened either due to power loss, that frequent.
and would just copy the actual file that resides over the sector
elsewhere and then copy it back. That would "clear it out".
Click to expand...

Utterly mangled all over again.
Again, this HDD is not physically damaged.
Click to expand...

Maybe not, but there is likely a bad physical sector.
I tested the drive with the manufacturer's Drive Fitnest Test, Spinrite,
S.M.A.R.T., and HDD Regen. There are no physical problems.
Click to expand...

Then your original claim has a problem. If there was a bad
sector due to power loss, it should have shown up there.
In fact, if it were a physically bad sector then that would be
a good thing -- as the drive would've just remapped that sector
to a reserve sector and I'd be able to copy with no problems.
Click to expand...

Yes, so your original claim has a problem.
Diagnostic software all reported there are plenty of reserve sectors
available.
Click to expand...
I ran chkdsk, from the recovery console as well. "Chkdsk /f" and
"chkdsk /r". The only thing chkdsk finds is one crosslinked file, which
seems to be located at exactly where this "bad" logical sector is.
Click to expand...

That shouldnt be happening either. A bad sector should just
see one file with a problem, the data in that particular sector.
In DOS/Win9x, chkdsk always gave the name of the actual crosslinked
file but with NTFS (WinXP), it is giving a file number. Is there a way to
determine the actual file from the file number it is giving? I'm pretty
confident that if this particular file was just copied, deleted, re-copied
it would clear up this "bad" logical sector.
Click to expand...

Your confidence is misplaced. Something else has happened.
 
Eric said:
Hi,

I just picked up a couple new drives and wanting to copy an entire partition
over to a new drive but have one bad logical sector that is causing the copy
to error out. This is a WinXP partition. This is not a bad physical
sector, but rather a "bad" logical sector. The HDD is not damaged. "Bad"
logical sectors result when the CRC value of a sector differ from the data
within, most likely a result from an inadvertent power cycle. If the HDD
were to be simply reformated, the "bad" logical sector would be removed. In
the DOS days, I remember getting some of these "bad" logical sectors every
now and then and would just copy the actual file that resides over the
sector elsewhere and then copy it back. That would "clear it out".

Again, this HDD is not physically damaged. I tested the drive with the
manufacturer's Drive Fitnest Test, Spinrite, S.M.A.R.T., and HDD Regen.
There are no physical problems. In fact, if it were a physically bad sector
then that would be a good thing -- as the drive would've just remapped that
sector to a reserve sector and I'd be able to copy with no problems.
Diagnostic software all reported there are plenty of reserve sectors
available.

I ran chkdsk, from the recovery console as well. "Chkdsk /f" and "chkdsk
/r". The only thing chkdsk finds is one crosslinked file, which seems to
be located at exactly where this "bad" logical sector is. In DOS/Win9x,
chkdsk always gave the name of the actual crosslinked file but with NTFS
(WinXP), it is giving a file number. Is there a way to determine the actual
file from the file number it is giving? I'm pretty confident that if this
particular file was just copied, deleted, re-copied it would clear up this
"bad" logical sector.

Thanks,
-Eric
Click to expand...

You can do a non destructive read/write surface scan with DiskPatch from
http://www.diydatarecovery.nl, but it isn't free. Indeed symptoms as you
describe them can be and have been 'fixed' using DiskPatch.

About the file number, in one of the resource kits there's a tool I think
called NFI.exe which can tell which files occupy which sectors on NTFS
partitions. Maybe it's also downloadable from the MS website somewhere.
 
Eric said:
Hi,

I just picked up a couple new drives and wanting to copy an entire partition
over to a new drive but have one bad logical sector that is causing the copy
to error out. This is a WinXP partition. This is not a bad physical
sector, but rather a "bad" logical sector. The HDD is not damaged.
Click to expand...
"Bad" logical sectors result when the CRC value of a sector differ from
the data within, most likely a result from an inadvertent power cycle.
Click to expand...

ECC, not CRC.
If the HDD were to be simply reformated, the "bad" logical sector would
be removed.
Click to expand...

Not really. There is actually very little writing in file system formatting.
In the DOS days, I remember getting some of these "bad" logical sectors
every now and then and would just copy the actual file that resides over
the sector elsewhere and then copy it back. That would "clear it out".
Click to expand...

If it was possible to copy then just that action alone would have cleared it.
Again, this HDD is not physically damaged. I tested the drive with the
manufacturer's Drive Fitnest Test, Spinrite, S.M.A.R.T., and HDD Regen.
Click to expand...
There are no physical problems.
Click to expand...

Then obviously there is no logical bad sector either.
In fact, if it were a physically bad sector then that would be a good thing
Click to expand...

Doesn't make a difference.
-- as the drive would've just remapped that sector to a reserve sector
Click to expand...

Nope, not with bad ECC.
and I'd be able to copy with no problems.
Click to expand...

Only if that sector was going to be bad but not quite yet (successful retries).
Bad ECC makes no diff, whether from physical bad or logical bad.
Diagnostic software all reported there are plenty of reserve sectors
available.
Click to expand...

Oh? That is interesting !? Didn't think that was possible.
I ran chkdsk, from the recovery console as well. "Chkdsk /f" and "chkdsk /r".
Click to expand...
The only thing chkdsk finds is one crosslinked file, which seems to
be located at exactly where this "bad" logical sector is.
Click to expand...

'Seems' and 'exactly' contradict each other ....
In DOS/Win9x, chkdsk always gave the name of the actual crosslinked file
but with NTFS (WinXP), it is giving a file number.
Click to expand...

.... and what does crosslinking have to do with a bad sector?
Is there a way to determine the actual file from the file number it is giving?
Click to expand...
I'm pretty confident that if this particular file was just copied,
Click to expand...

That is not likely, because of that bad ECC "bad" sector.
But since there is no such bad sector (logical nor physical) anymore, why bother?
deleted, re-copied it would clear up this "bad" logical sector.
Click to expand...

You just said it wasn't there anymore (Drive Fitnest Test, Spinrite, S.M.A.R.T.,
and HDD Regen), so that is not the problem.
Problem likely is the file system recorded bad cluster.
That needs another approach.
 
You can do a non destructive read/write surface scan with DiskPatch from
http://www.diydatarecovery.nl, but it isn't free. Indeed symptoms as you
describe them can be and have been 'fixed' using DiskPatch.

About the file number, in one of the resource kits there's a tool I think
called NFI.exe which can tell which files occupy which sectors on NTFS
partitions. Maybe it's also downloadable from the MS website somewhere.
Click to expand...

Thanks!

I found "NFI.EXE" at
http://www.rockstar.anubis.eu.org/pliki/soft/winhex/?C=N;O=D and it is
giving some good clues.

Cheers,
-Eric
 
I suggest you use Partition Table Doctor to resolve your
problem.The software provides very useful functions:
Backup partition table, Restore partition table, Rebuild
partition table, undelete partition, Fix boot sector,
rebuild mbr,etc.

First thing I recommend you download the demo version of
Partition Table Doctor.( http://www.ptdd.com/download.htm )

Run the program and right click the partition and choose fixboot.
http://www.ptdd.com/fixboot.htm
 
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