Hi,
I finally found the root cause and it's my fault.
Cron is really not there because my engineer used to change the version of MySQL from embedded to community.
He uses yum to uninstall MySQL so several dependency packages have been removed
If somebody encounters the same situation, here's the workaround.
- download these packages.
sendmail-8.14.4-9.el6_8.1.x86_64
cronie-1.4.4-16.el6_8.2.x86_64
cronie-anacron-1.4.4-16.el6_8.2.x86_64
crontabs-1.10-33.el6.noarch
- install sendmail first.
- install cronie-1.4.4-16.el6_8.2.x86_64 with --nodeps (It shows error if --nodeps is not there.)
- install crontabs-1.10-33.el6.noarch
- install cronie-anacron-1.4.4-16.el6_8.2.x86_64
-Done
Thanks all of you