File System Corruption

QNX Newsgroups (Archives) qdn.public.qnx4
#1

Hi,
I have had file system corruption on a few units before, usually Lost Links
(unrecoverable by chkfsys, so I have to go in and manually repair the
problem). I was reading through the helpviewer documentation on the file
system and was considering whether I could write a program that might
recover a lost link. Does anybody know what causes them, which data becomes
corrupt, and if it’s even possible to repair the lost links? I’ve been
trying to determine just what causes them, but so far each case I have had
makes them pop up in different locations (and some in areas my software
doesn’t even go).

Any help is appreciated. It would be really great to not have to manually
repair these anymore and to be able to just run a small app and let it fix
it for me.

TIA!

R B Adler

#2

By a “lost link” you mean a directory link? Usually these
do not go away by themselves. There are two broad categories
of problems that might cause this.

  1. You are powering down in the middle of an update

  2. You have a bad disk, or the disk driver is not working
    properly on your hardware.

You will probably know if the problem is item 1). Even if you are
powering down, supposedly Fsys does things in an order that would
leave you reasonably ok, and not lose an existing link.


Previously, R B Adler wrote in qdn.public.qnx4:

Hi,
I have had file system corruption on a few units before, usually Lost Links
(unrecoverable by chkfsys, so I have to go in and manually repair the
problem). I was reading through the helpviewer documentation on the file
system and was considering whether I could write a program that might
recover a lost link. Does anybody know what causes them, which data becomes
corrupt, and if it’s even possible to repair the lost links? I’ve been
trying to determine just what causes them, but so far each case I have had
makes them pop up in different locations (and some in areas my software
doesn’t even go).

Any help is appreciated. It would be really great to not have to manually
repair these anymore and to be able to just run a small app and let it fix
it for me.

TIA!

R B Adler
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–
Mitchell Schoenbrun --------- maschoen@pobox.com