服务器没有装NTP，要每天向特定的server进行时间同步，写了一个定时任务，放在/etc/cron.daily下，但是不运行。
/etc/crontab文件：
# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the `crontab'
# command to install the new version when you edit this file
# and files in /etc/cron.d. These files also have username fields,
# that none of the other crontabs do.
SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
# m h dom mon dow user command
17 * * * * root cd / && run-parts --report /etc/cron.hourly
25 6 * * * root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )
47 6 * * 7 root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly )
52 6 1 * * root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.monthly )
/etc/cron.daily/ntpdate
/usr/sbin/ntpdate 10.1.1.41 >> /var/log/ntpdate.log 2>&1
最后google出来需要在ntpdate脚本上添加#!/bin/sh