Panic - cannot get a dump

[Stephen Montgomery-Smith]

Bob Johnson wrote:

> 
> Any chance your RAID array is built from two-year-old Western Digital 
> drives?  Your problem sounds a lot like the one discussed here:
> http://adam.kungfoohampster.com/lists/freebsd-questions/msg18877.shtml
> 
> The message above doesn't mention it, but the WD KB article also 
> includes a fix for drives on 3Ware controllers.
> 

Probably this is not the problem.  I have Seagate drives, and the 
symptoms seem to be different - I have a panic, not a freeze.

Although I am having problems with the disk when I reboot.  The program 
I am running outputs a "data.check" file every second or so, so that 
when the program is restarted it can pick up where it left.  The code to 
do this is something like
   check_point = open("data.check-tmp",O_WRONLY|O_TRUNC|O_CREAT,0644);
   write(check_point,lots-of-stuff);
   close(check_point);
   rename("data.check-tmp","data.check");
What I find is that after the panic the file "data.check" is several 
days old.  I am guessing it is because the IDE Seagate disk has some 
cache that it doesn't write back to the disk - probably it is the 
directory itself which is not properly updated.  It is a bit annoying, 
but I can live with this.  But maybe this indicates something more sinister.



I have put in another IDE disk whose only purpose is to be the disk to 
dump to.  Hopefully I will be able to catch a good dump on that.

-- 

Stephen Montgomery-Smith
stephen at math.missouri.edu
http://www.math.missouri.edu/~stephen