Linux Tools for rebuilding a FAT16 or FAT32 file system

Jeremy jepri at webone.com.au
Fri Mar 29 13:19:14 EST 2002


> Why complicate the matter by crossing over O/Ses?

Because Linux deos it better?


> > Ummm.  If the FAT table was changed, you probably lost all the
> > information therein.  Which means that the clusters on the disk now
> > have no relation to each other, and your files are broken up into
> 4kb
> > chunks.  However you may be lucky.  If the files aren't fragmented
> you
> > might be able to do a 'strings /dev/hdxx' and start playing jigsaw
> > puzzles.
> 
> Arent't there two copies of the FAT tables? I was under the impression
> that
> was how the recovery programs managed to rebuild it.

Kind of.  The FAT tables are supposed to be mirror images of each other 
at all times.  The backup is handy, but if you went in with fdisk and 
repartitioned the drive, both FAT tables would have the same, new, 
partition scheme.  How could it be any other way?  The mirror table is 
to prevent corruption occurring when you power off halfway through 
writing to the FAT, and even then it was useless, because there was no 
way of telling which table you were writing to when the lights went out.

Most of those recovery programs are fairly useless.  They are a pretty 
front end bolted onto a program that returns one two messages:

1)  Everythings fine
2)  Time to format and reinstall

All the progress bars and whatnot are just there to impress the user.  
No MS filesystem has good error recovery, although NTFS has a decent 
try at it.




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