Albert wrote: ...
Thx for the answered, but the centos have commercial support like RHEL?
CentOS itself is a volunteer non-commercial effort. If you want a paid-support OS RHEL is highly recommended, and CentOS would not exist without them.
There are also companies that offer commercial support for CentOS - google "centos commercial support" and you will find some. One that I happen to know actively participates in CentOS is
http://www.owlriver.com/support/centos/
Phil