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tavikas

$BadClus:$Bad

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I am using defraggler v1.08.132.

 

The partition I am talking about here is 33,6GB. (both MS and Defraggler)

After analyzing a drive, in first block (which is red) there are file called $BadClus:$Bad. According to defraggler, this single file has 2 fragments and it is 35 214 448kB. The drive (partition) has 11% free space...

 

The results of different tests by different disk tools are all saying - no problems found. Neither are there any problems using a disk (this is a system partition - NTFS and Windows XP Home SP3).

 

Why does defraggler identify this file as big as whole partition? What is this file at all?

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I just noticed this same problem after installing the latest version 109 software. I uninstalled 109 and reinstalled 108 to see if it was an error in the version but I still have the $BadClus:$Bad fragments. I have a smaller 80GB drive on my laptop. selecting a list of the files for almost any location on the drive map, including free space, indicates a fragment of 78,148,160 Kb with a path of C:\ . There are light blue shaded locations that list only that $BadClus:$Bad fragment . Running chkdisk does not indicate any errors on the drive. However I don't seem to be able to defragment large files associated with the game application World of Warcraft. A number of these games files exceed 2GB. Current analysis indicates 24% free space, 28% fragmentation in 42 fragmented files with 203 fragments occupying 15.5 GB of space. What exactly is the $BadClus:$Bad Code intended to indicate?

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There is nothing wrong with your file system or your disk (if chkdsk says so), but let me explain it from the very beginning.

 

First versions of NTFS were created about 15 years ago. That time the hard disks didn't have a built-in functionality for marking damaged clusters. It had to be supported by the file system. That was the purpose of creating $BadClus metafile (metafile is a special file system structure - intended for the internal use).

 

Please note that $BadClus is a sparse file which has the size equal to the size of the whole file system. A sparse file is a file of bigger size than actually allocated on the disk - it's filled with zeros and treated similarly to a compressed one. So even though it reports to have several gigs, it may have no space allocated at all.

 

Now, when the file system detected that a cluster is damaged it allocated it to the $BadClus:$Bad ($Bad is a named stream) file, so it couldn't be used by any other file.

 

Now the most important part ;) : Modern hard disks have this feature built-in. The firmware automatically detects bad clusters and mark them as damaged, so they won't be used again. It does it instantely, so the file system doesn't even notice anything. That means that currently $BadClus:$Bad is not used and it is empty (although its "virtual" size is equal to the partition size).

 

Best regards

romanoff

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There is nothing wrong with your file system or your disk (if chkdsk says so), but let me explain it from the very beginning.

 

First versions of NTFS were created about 15 years ago. That time the hard disks didn't have a built-in functionality for marking damaged clusters. It had to be supported by the file system. That was the purpose of creating $BadClus metafile (metafile is a special file system structure - intended for the internal use).

 

Please note that $BadClus is a sparse file which has the size equal to the size of the whole file system. A sparse file is a file of bigger size than actually allocated on the disk - it's filled with zeros and treated similarly to a compressed one. So even though it reports to have several gigs, it may have no space allocated at all.

 

Now, when the file system detected that a cluster is damaged it allocated it to the $BadClus:$Bad ($Bad is a named stream) file, so it couldn't be used by any other file.

 

Now the most important part ;) : Modern hard disks have this feature built-in. The firmware automatically detects bad clusters and mark them as damaged, so they won't be used again. It does it instantely, so the file system doesn't even notice anything. That means that currently $BadClus:$Bad is not used and it is empty (although its "virtual" size is equal to the partition size).

 

Best regards

romanoff

 

I have the problem that you described and it is comforting to know that this is normal but I see that not all hard drives have this issue and in some cases it creates a problem when the $BadClus:$Bad will not move to a new location and therefore creates a problem with creating a large enough Page File without major page file fragmentation. Occasionally I have seen the $BadClus:$Bad go away after Defraggler's Advanced, "Check Drive for Errors" is run or CHKDSK, but not always. Is there anything that can be done to move these $BadClus:$Bad to different locations were this would allow space for the Page File. I have noted that at least sometimes reformatting the drive seems to help as does running Ghost to another drive then reuse the drive that was a problem; which of course takes a lot of time and effort. Defraggler is a fantastic product. Keep up the good work.

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I have the problem that you described and it is comforting to know that this is normal but I see that not all hard drives have this issue and in some cases it creates a problem when the $BadClus:$Bad will not move to a new location and therefore creates a problem with creating a large enough Page File without major page file fragmentation. Occasionally I have seen the $BadClus:$Bad go away after Defraggler's Advanced, "Check Drive for Errors" is run or CHKDSK, but not always. Is there anything that can be done to move these $BadClus:$Bad to different locations were this would allow space for the Page File. I have noted that at least sometimes reformatting the drive seems to help as does running Ghost to another drive then reuse the drive that was a problem; which of course takes a lot of time and effort. Defraggler is a fantastic product. Keep up the good work.

 

If I recall correctly, /B is a CHKDSK command you can run to check for bad clusters on your drive. However, I also seem to remember that it would not work under the SP3 of XP.

 

Of course, if you really need to move it, have you tried running Cedrick Collomb's Unlocker to move it? That program is marvelous. It has been able to move files that you cannot normally move in windows. Including Webroot locked definition files, or in certain cases, windows files that windows could not delete/move/open.

 

Let me know if this helps!

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If I recall correctly, /B is a CHKDSK command you can run to check for bad clusters on your drive. However, I also seem to remember that it would not work under the SP3 of XP.

 

Of course, if you really need to move it, have you tried running Cedrick Collomb's Unlocker to move it? That program is marvelous. It has been able to move files that you cannot normally move in windows. Including Webroot locked definition files, or in certain cases, windows files that windows could not delete/move/open.

 

Let me know if this helps!

 

Er, you don't want to move a bad cluster, as the whole point is to disable using it because it's bad!

 

A better option would be to have defraggler not display the bad clusters. It can't use them or move them, so why even tell us they are there?

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