Help! recovering video files from filexxxx.chk.

Archived from groups: rec.video.desktop (More info?)

Something happened to one of my hard drives, running on win2k, and many
..avi & .mpg files wound up in a subdirectory called found.000. They are
all sized in multiples of 32,768 bytes and are named filexxxx.chk. I
have tried renaming the .chk suffix to .mpg or .avi and have saved some
of them this way, trying realplayer, winmediaplayer, & divx. Others only
generate error messages when I try to play them after changing the
suffix. Is there a more logical way to go about trying to recover these
files?
Any help will be greatly appreciated.
Tom

Archived from groups: rec.video.desktop (More info?)

On 4/23/2005, thomasgraham managed to type:
> Something happened to one of my hard drives, running on win2k, and many .avi
> & .mpg files wound up in a subdirectory called found.000. They are all sized
> in multiples of 32,768 bytes and are named filexxxx.chk. I have tried
> renaming the .chk suffix to .mpg or .avi and have saved some of them this
> way, trying realplayer, winmediaplayer, & divx. Others only generate error
> messages when I try to play them after changing the suffix. Is there a more
> logical way to go about trying to recover these files?
> Any help will be greatly appreciated.
> Tom

You have a problem (understatement). What you have done is correct,
however...

But - files are not necessarily stored in a single contiguous piece of
the disk, so it is probable that many or all of the file*.chk are not
complete files but segments of complete files, depending on what the
crash was and how chkdsk (or whatever) identified the chunks. Oh, and
the 32k granularity of the reported sizes is a direct consequence of
the cluster size on your hard drive. Cluster size is the unit of disk
memory that the file system uses to allocate space. The size is always
512 times some power of two, depending on the size of the partition and
the file system you are using.

Your task is to identify which set of chunks goes with one original
file, and to combine that set in the correct order into a single file,
then do the same for each of the remaining original files.

This is not easy...

Having said the above, I wonder if you could Google for a file recovery
utility that would help in the process. The success might depend a lot
on whether you have a FAT or NTFS file system. I have no opinion there,
except a feeling that NTFS might be better. However, I'm not sure if
NTFS produces this kind of file fragments after a crash.

One good thing: you do have the file*.chk files. If you had not run the
check utility until after a bit of disk activity, it is possible that
many of the lost fragments could have been overwritten. No, I'm most
likely wrong there, I think, since the fragments must have been marked
as not available.

Also, perhaps dome of the chunks were not originally video files, but
other files that also got lost. That would explain them not playing.

Good luck, and let's hope for more useful remarks from other people
here.

Gino

--
Gene E. Bloch (Gino)
letters617blochg3251
(replace the numbers by "at" and "dotcom" )