WITH_OPTIMIZED_CFLAGS=yes
WITH_OPTIMIZED_CXXFLAGS=yes
#ftp://ftp.freebsdchina.org/pub/FreeBSD/ports/distfiles/${DIST_SUBDIR}/ \
MASTER_SITE_BACKUP= \
ftp://ftp.tw.FreeBSD.org/pub/FreeBSD/ports/distfiles/${DIST_SUBDIR}/ \
ftp://ftp.freebsdchina.org/pub/FreeBSD/ports/distfiles/${DIST_SUBDIR}/ \

BSD 4.11
options ACCEPT_FILTER_HTTP
options ZERO_COPY_SOCKETS
options PANIC_REBOOT_WAIT_TIME=0
options QUOTA

cvsup standard-supfile
make buildworld
make buildkernel KERNCONF=changlong
make installkernel KERNCONF=changlong
mergemaster -p
make installworld
mergemaster

reboot

停止原系统的主要服务，或者重启后进入单用户状态，准备复制。进入单用户模式的方法：1.重启，在启动菜单开始倒计时的时候按下空格(space)键，输入boot -s ，