ZFS-Only FreeBSD and crashdump

Thu Apr 28 16:01:53 UTC 2011

I have the ZFS-Only FreeBSD 8.2.
# gpart show
=>       34  321672893  ad4  GPT  (153G)
          34        128    1  freebsd-boot  (64K)
         162   33554432    2  freebsd-swap  (16G)
    33554594  288118333    3  freebsd-zfs  (137G)

How to obtain crash dump, so he kept on zfs?
Is it enough for it to correct /etc/rc.d/zfs, adding:
"# BEFORE: dumpon" ?

-- 
Vladislav V. Prodan
VVP24-UANIC
+380[67]4584408
+380[99]4060508
vlad11 at jabber.ru