fsck and dump freeze freebsd. any ideas?

[DA Forsyth]

On 29 Jul 2009 , freebsd-questions-request at freebsd.org entreated 
about
 "freebsd-questions Digest, Vol 269, Issue 6":

>   After one of the last crashes, the system would lock up a short time
> after rebooting. I found the problem caused by background fsck locking
> up the system. I took the partition out of the startup check for now.
> I 'think' I was installing a port during the last crash, but it has
> been a while. I performed a fsck and a dump (to /dev/null) confirming
> that both do crash the freebsd 7.2 and 6.2 (which I booted off of a
> separate drive). A tar to /dev/null did run successfully, but I recall
> reading that that is not a recommended way to backup/move a
> filesystem. The /usr partition where it causes trouble is in a raid5
> geom_vinum three drive array. I did not yet have the array rebuild the

My experience has been that dump *with snapshot* of a live filesystem 
will crash if the filesystem is 'large'.  MY solution is to umount 
the partition.  This happens with my 800GB /home which is part of a 4 
drive raid5 array (ar driver with hardware setup).  It used to happen 
with the previous 320GB mirror array too, just with /home which is 
the biggest partition.   This is one reason I moved away from tape 
backup to a secondary server full of harddrives as backup target, the 
tape took far too long with /home unmounted and users were affected.

As for the fsck crashing, I'm lost.  Maybe a faulty drive?  




--
       DA Fo rsyth            Network Supervisor
Principal Technical Officer -- Institute for Water Research
http://www.ru.ac.za/institutes/iwr/