Corrupt files with perc 4/dc

[Jerlique Ban]

Hello,

I have a dell power edge 2650 with a perc 4/dc raid controller which
connects to a powervault 220s storage system.  I am running FreeBSD v4.9.

I am experiencing some problems with file corruption, when I abruptly reboot
the system (in order to simulate power failure).

I have tried turning off soft updates and setting write-thru mode (suffering
a huge performance hit), but neither have help.

I would appreciate it some one can offer some suggestions as to why I
experience these problems.

Thanks.