If you are trying to use razor to install CentOS and are running issues with the chef broker hand off, it is likely that this failure is cause the clock difference between your chef client and chef server. To verify, after install of OS is complete, log into your new node and run chef-client.

[root@centos9 ~]# chef-client
 Starting Chef Client, version 11.4.4
 [2013-08-23T07:42:02-06:00] INFO: *** Chef 11.4.4 ***
 [2013-08-23T07:42:02-06:00] INFO: [inet6] no default interface, picking the first ipaddress
 Creating a new client identity for centos9.razor.one using the validator key.
 [2013-08-23T07:42:03-06:00] INFO: Client key /etc/chef/client.pem is not present - registering
 Chef encountered an error attempting to create the client "centos9.razor.one"
Authentication Error:
 Failed to authenticate to the chef server (http 401).
 The request failed because your clock has drifted by more than 15 minutes.
 Syncing your clock to an NTP Time source should resolve the issue.

Once the server is installed, fixing this issue is simple. Log in to the server, install ntpdate, and correct the date:

yum install ntp
ntpdate pool.ntp.org

running chef-client again will be succesful.

However, this is not good enough for automated installs, it would be great if Razor did this to begin with. To correct it, edit file https://github.com/puppetlabs/Razor/blob/master/lib/project_razor/model/redhat/6/os_boot.erb

Before adding puppetlabs repo, add these two lines:

yum -y install
ntpntpdate pool.ntp.org

This should be in a patch on github, but it appears that no recent patches have been accepted to the current razor code.