NTFS bad blocks errors in the event viewer

Question

I have a Dell 510m with XP and a Toshiba HD. There are a few bad blocks which I can see with the Diagnostic CD. They haven't got worse over the last few years. Recently I saw some "Bad Block" errors in the event viewer. The diianostic CD shows me one more bad block than before.

My question is: When the Bad Block error appears, does that mean that the NTFS filing system has marked that block as bad so it doesn't get used again?  If not, will CHKDSK (the /R option?) find the new bad block and mark it unusable?  If not, is there a way to do this?

There is no option to replace the HD. I just need to keep this laptop going long enough to decide what to buy to replace it.

Thanks

Peter

Answer 1

Peter

24 KB in bad sectors. = 6 clusters so it is presently not a serious problem. However, you need to check regularly for a while to make sure that the number does not increase.

Of course any bad cluster can be bad news if it coincides with the location of a vital system file.

You should also use chkdsk to effect repairs as per this part of the report:

Correcting errors in the Volume Bitmap.

Windows found problems with the file system.

Run CHKDSK with the /F (fix) option to correct these.

Use Edit, Find with Volume Bitmap as the Search Criteria for further information:

http://en.wikipedia.org/wiki/Hierarchical_File_System

Answer 2

Peter,

 I've been told by a number of other community stars that the HD controllers do in fact do the bad sector recovery automatically under "normal" circumstances.  I was as surprised as you to hear that because I'm pretty sure it wasn't always that way.   I don't remember hearing about that until about a year ago, and I remember doing it with CHKDSK back in the DOS/FAT days like you do.  New HDs come with spare sectors set aside for recovery purposes when these things occur.  Windows will automatically mark any sectors as bad as it finds them, but the messages you get could vary depending on what you happen to be doing at the time.  This is of course assuming the HD controller doesn't do it transparently. 

 It's not that big a hassle to replace a hard drive, I've done it before on several occasions.  You just need a good backup/restore program (I use Norton Ghost, but there're many others as well).  I don't recommend the Windows supplied one though) to back up your current drive, remove and replace the old drive.  Format the new drive, then restore from your backup.

 Good luck.

Answer 3

Gerry:

Here's my CHKDSK report a few moments ago. Run WITHOUT /F or /R so that I can see the report!  It took CHKDSK far less time to do this than a full read of the HD would have taken, so I assume that the 24kB in bad sectors is what the filing system has ALREADY marked as bad. I suppose running it again with /F would "correct the problems" but I think only /R would scan the whole disk for bad sectors and I assume it needs to restart to do that and I won't see the report.  My question is whether NTFS has ALREADY marked the Bad Block which it told me about, so I don't need to run CHKDSK /R every time I see a Bad Block message.

Regards

Peter

===

The type of the file system is NTFS.

WARNING!  F parameter not specified.

Running CHKDSK in read-only mode.

CHKDSK is verifying files (stage 1 of 3)...

File verification completed.

CHKDSK is verifying indexes (stage 2 of 3)...

Index verification completed.

CHKDSK is verifying security descriptors (stage 3 of 3)...

Security descriptor verification completed.

CHKDSK is verifying Usn Journal...

Usn Journal verification completed.

Correcting errors in the Volume Bitmap.

Windows found problems with the file system.

Run CHKDSK with the /F (fix) option to correct these.

  55633094 KB total disk space.

  32476104 KB in 104918 files.

     37200 KB in 7490 indexes.

        24 KB in bad sectors.

    283522 KB in use by the system.

     65536 KB occupied by the log file.

  22836244 KB available on disk.

      4096 bytes in each allocation unit.

  13908273 total allocation units on disk.

   5709061 allocation units available on disk.

Answer 4

Hula_Baloo:

I am sure you are right about HD controllers patching bad sectors - certainly they would do this in the factory - but if they were able to do this 'on the fly', then they would not report "Bad Sector" to the filing system, they would just patch in a spare and, apart from a one-time glitch, you would never be aware of it unless it had no more spare sectors!  Since we DO see Windows reporting "Bad Block", I am supposing that the HD controller is not that clever and it is left to the filing system to deal with bad sectors which develope during the life of the drive. Hence my question: "Does NTFS do this when it finds a bad block?"  Of course, since it found the block bad, it will have corrupted the file - that's down to the end-user to fix.

I have tried to find a replacement HD but these are well obsolete, so I will eventually have to replace the PC itself. But if this HD is only deteriorating slowly, maybe it's life isn't over yet.

Regards

Peter

Answer 5

grc.com's spinrite takes care of bad blocks - you should turn on SMART (if it doesn't already do it) in your BIOS because it may not be on.

spinrite might recover your system too. it did for a client's laptop where the disk was pretty far gone. it tries to treat the disk as analog data. works with SSD's and floppies too. but ask about what level to use on SSD's first.

version 6 takes 2-150 hours and doesn't work on disks over 2TiB. best tool in the biz. uses FreeDOS to boot (I make my disk utilities the same way, I need DOS on a cdrom, since I must not have the host OS running!). the newer version won't be going through the BIOS so should be much speedier.

$89