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I have intermittent bad block errors in my Windows SBS 2003 system event log. The error description is The device, \Device\Harddisk4, has a bad block, and I would like to be able to authoritatively say which physical disk that is. Or in other words, can someone tell me how to authoritatively determine which physical disk a \Device\HarddiskX description refers to?

I belive it may be that the Harddisk4 maps to "Disk 4" in the Disk Management utility, but I have not found any reference saying that it is so in so many words.

My system configuration is as follows, from a Disk Management perspective, and all SATA disks:

Disk 0: Windows C: (actually a hardware mirror)
Disk 1: Data D: (software mirror with Disk 2)
Disk 2: Data D: (software mirror with Disk 1)
Disk 4: My Book G: (Western Digital 1TB USB disk, used for nightly backups)
CD-ROM 0: E: (DVD Writer)
CD-ROM 1: WD Smartware (Virtual drive on WD 1TB disk, no letter assigned)

I have spent some time searching, but the only info I have found is to "look in disk management" but that is not definitive enough for me to say "this disk is faulty".

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up vote 1 down vote accepted

as per

In disk management Disk x refers to \Device\Harddiskx

So unsurprisingly it is your portable HD that had the bad block.

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Thanks. I had read that KB, but not studiously enough. Point (2) for Windows 2000 and later systems reads "View the graphical view of your disks. Right-click the gray portion of the basic or dynamic disk whose disk number matches the "Harddisk#" in the error message." – Nicolas Jun 22 '10 at 13:21
Yes, I am not surprised that it would be the portable disk, but better to be sure than assume! – Nicolas Jun 22 '10 at 13:22

Because "disk 4" seems to be the backup disk. Can you correlate the time of the errors to the time of your backup process? If so, then perhaps you can choose to 'not run' the backup for a single night and see if the errors vanish.


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Not really. (1) It's a terabyte drive storing the most recent five backups. (We archive the most recent backup offsite once a week) This issue only occurs occasionally as in about once a month, which I suspect is when the backup happens to try to write on the portion of the disk where the bad blocks are. The next backup has always run fine again. – Nicolas Jun 22 '10 at 13:29
(2) I was wondering if the USB interface was part of the problem, since I note four "controller errors" in amongst the block of 19 bad block errors. – Nicolas Jun 22 '10 at 13:32
(3) Yes the fault does occur within 15min of the backup starting. But the backup log reads like this: "WARNING: Portions of "\WINDOWS\system32\" cannot be read. The backed up data is corrupt or incomplete. This file will not restore correctly." Which to me means that it could not read successfully from my system partition, not that there was a fault on the backup media. – Nicolas Jun 22 '10 at 13:35

The number in the DRx part at the end really does not have any special meaning. It is just a sequence number which starts at 0 and increases ever since. That means it matches the preceding HarddiskX part after boot, but if you plug or unplug some drives, the number keeps increasing and naturally gets out of sync.

As for pinpointing the exact disk from a path like \Device\Harddisk1\DR3, this works for me:

Download WinObj from Sysinternals
Run it as administrator
Go to \Device\HarddiskX
You will see individual PartitionY symbolic links (to \Device\HarddiskVolumeZ), note these down
Go to \GLOBAL??, sort by the 3rd column "SymLink"
Find the \Device\HarddiskVolumeZ value you noted down in the 3rd column
You will see various names of that volume in the first column, including HarddiskXPartitionY, Volume{GUID} and (what's probably most useful for most people) the DOS-style letter like C:
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