Panic "softdep_move_dependencies: need merge code"

[Andrew Liles]

I have a Highpoint RocketRAID 454 card configured for RAID5 with 4 discs 
(driver is hpt374.ko) on FreeBSD 5.2.1-RELEASE.  I have had a history of 
panics that I think emanate from the filesystem and I have far more 
physical failures of the discs than one might expect (I suspect heat damage 
due to poor ventilation).

Having built myself a debug kernel I was able to pinpoint the following in 
3 recent panics that occurred within a few days of each other.  Around this 
time I found that another disc has died on me.

In all cases I believe the panics occur under periods of intense disc 
activity; e.g. copy many files from one area to another, or running big 
meta-data updates like chmod -R and chgrp -R.

This the instruction that calls the panic:

#14 0xc0776904 in softdep_move_dependencies (oldbp=0xcd0d9c20, 
newbp=0xcd0c0838) at ../../../ufs/ffs/ffs_softdep.c:800
800                     panic("softdep_move_dependencies: need merge code");

I have read this post:
http://tinyurl.com/c3fpj

a) Is it reasonable to assume that my panics are exactly because I have 
suffered physical disc problems/
b) shouldn't my external RAID5 have insulated me from such issues?
c) might there be some incompatibility with Soft Updates and this 
particular RAID5 implementation?

I am happy to forego the benefits of SoftUpdates if I can then have a 
stable machine.

What would you recommend?

Andrew Liles