fst

Unlike CHKDSK, fst does not fix the errors it finds (except for `check -fix=z').

I wrote fst after a HPFS partition was corrupted by an HPFS bug three times in a single day. I wanted to know exactly what's going wrong.

Why another CHKDSK? Well, CHKDSK has several problems:

• CHKDSK does not show the names of all files known to be corrupt (or corrupted by CHKDSK). For instance, if n files share data sectors, the names of only n-1 files are printed; CHKDSK won't tell you about one file which is probably damaged out of each group of files sharing sectors
• CHKDSK sometimes corrupts the file system even more than it was before running CHKDSK. fst can save a snapshot of all relevant sectors to a file. After running CHKDSK, you can compare the disk to the snapshot file to find out what sectors have been changed by CHKDSK. You can even restore the sectors from the snapshot file to the disk to undo CHKDSK's fixes.
• CHKDSK sometimes gives false alarms, complaining about errors which don't exist and which it won't fix. For instance, CHKDSK apparently has problems with extended attributes of type 2 (FNODE pointing to an ALSEC).
• CHKDSK cannot fix certain types of HPFS corruption (for instance, sectors shared by Spare DIRBLKs and extended attributes). To be able to fix the errors manually with a sector editor, one needs to know exactly what's wrong. For each defect, fst prints the relevant sector numbers.

Nowadays, the main purpose of fst is to fix filesystem problems on CompactFlash cards written by PSION handhelds (running EPOC) so that those CompactFlash cards can be written to by other systems without trashing the filesystem.

Click here to go to the project page.

Downloading and Installing

• fst05b.zip
• emxuser-20041223.zip, required under EPOC