What is system file $BadClus$Bad:$DATA?

My disk defragmenter show this file as one of the few fragmented ones on
one of my drives. It lists its size as 97 GB which happens to be listed
size of the whole partition!

Jason wrote:
My disk defragmenter show this file as one of the few fragmented ones on
one of my drives. It lists its size as 97 GB which happens to be listed
size of the whole partition!


Of course it's fragmented. Working as designed.

That's a map of the entire partition, showing which
clusters have been mapped out due to CRC errors. It's a
"sparse" file, so it takes "no space". Only the cluster
mapped out, takes physical space, and "plays its own
part in the movie". So really, nothing is moved. It's
just a representation of a cluster the file system no
longer trusts or wants to use.

Since clusters can go bad at random locations, the
file will appear gap-toothed/fragmented. But it's
a sparse file, so it is "32KB on disk", "97GB size".
The size on disk is minimal. The virtual size, large.

Only if every cluster had failed, then the 97GB $BADCLUS
would take 97GB of space, and there'd be no gaps.

As you can imagine, there will be times when you want
to know more about that metadata file. For example, if you "clone"
a partition, from a bad hard drive to a good hard drive,
depending on how the clone is done, you can drag the
mapping of bad clusters with it. Which isn't really what
you want to happen. More research is required, to get
that handled properly. While I would expect a Macrium clone
to not copy it, well, you'd better test and check, just
to see. Unless you have a partition with bad clusters
on it, you may not have the materials to do such a test
before hand.

Paul

On Sun, 02 Apr 2017 22:07:39 -0400, Paul
wrote:

As you can imagine, there will be times when you want
to know more about that metadata file. For example, if you "clone"
a partition, from a bad hard drive to a good hard drive,
depending on how the clone is done, you can drag the
mapping of bad clusters with it. Which isn't really what
you want to happen. More research is required, to get
that handled properly. While I would expect a Macrium clone
to not copy it, well, you'd better test and check, just
to see. Unless you have a partition with bad clusters
on it, you may not have the materials to do such a test
before hand.

In this case run chkdsk with the /b option.

/b NTFS only: Clears the list of bad clusters on the volume and
rescans all allocated and free clusters for errors. /b includes the
functionality of /r. Use this parameter after imaging a volume to a
new hard disk drive.

https://technet.microsoft.com/en-us/...(v=ws.11).aspx

--
Gianni

On Mon, 03 Apr 2017 14:44:39 +0200 "Gianni Turri" removethisgiannit62
@andthisgmail.com wrote in article 4qg4ecp3tb7vprh4qdj8vvdunr2nv138de@
4ax.com
In this case run chkdsk with the /b option.

/b NTFS only: Clears the list of bad clusters on the volume and
rescans all allocated and free clusters for errors. /b includes the
functionality of /r. Use this parameter after imaging a volume to a
new hard disk drive.

https://technet.microsoft.com/en-us/...(v=ws.11).aspx

--
Gianni



Thanks!