I rebuilded a new kernel image and copy the modules file in /lib/modules/.Finaly I removed the dhclient which is in /usr/bin/ and I can always boot the rootfs from the nfs server.   ^_^ 

Regards 
--- 10年12月13日，周一, tuxdna <tuxdna@gmail.com> 写道：

发件人: tuxdna <tuxdna@gmail.com>
主题: Re: [fedora-arm] fedora12 rootfs nfs
收件人: "钟威" <zhongw_1984@yahoo.com.cn>
日期: 2010年12月13日,周一,下午2:55

On Wed, Dec 8, 2010 at 4:21 PM, 钟威 <zhongw_1984@yahoo.com.cn> wrote:

Hi guys,     I have a problem,when I boot fedora12 arm rootfs from my nfs server which can boot successfully.But when I boot it second time,I cannot boot it anymore.The error is which is hanging on "Starting udev".So, any suggestions?

I see that rootfs-f12 doesn't have kernel modules installed in /lib/modules. Have you checked that ? Maybe this is the reason it doesn't work.

/tuxdna