boot0cfg -B can't work

I want to rewrite boot0 into mbr but failed, infos follows:

# boot0cfg -B ad2
boot0cfg: write_mbr: /dev/ad2: Operation not permitted

# ls /dev/ad*
/dev/ad2     /dev/ad2s2   /dev/ad2s2b  /dev/ad2s2e  /dev/ad2s2g
/dev/ad2s1   /dev/ad2s2a  /dev/ad2s2d  /dev/ad2s2f  /dev/ad2s3

> uname -a
FreeBSD bsd.hasee.cpu 8.2-PRERELEASE FreeBSD 8.2-PRERELEASE #0: Sun
Dec  5 19:14:33 CST 2010
root@bsd.hasee.cpu:/usr/obj/usr/src/sys/HASEE  i386

-- 
Regards,
Yue Wu

Key Laboratory of Modern Chinese Medicines
Department of Traditional Chinese Medicine
China Pharmaceutical University
No.24, Tongjia Xiang Street, Nanjing 210009, China
_______________________________________________
freebsd-stable@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org"