How to create users' home directory by using "pam_mkhomedir.so" module if it does not exist in autofs ?

Environment

• Red Hat Enterprise Linux 6

  Assume that there are 3 machines: machineA as NFS server,machineB as autofs server and machineC.

• Create and share a directory in machineA(NFS server).

      # vim /etc/exports
      /export/home   *(rw,sync,no_root_squash)
  

• Configure autofs in machineB.

  1. Configure auto.master.

     # vim /etc/auto.master
     /mnt/home   /etc/auto.home
     

  2. Configure auto.home.

     # vim /etc/auto.home
     home            /             -rw   192.168.122.10:/export/home 
     or
     home            /nic          -rw   192.168.122.10:/export/home/nic
     

  3. Configure password-auth.

     # vim /etc/pam.d/password-auth 
     (Change the line that has the keyword "optional" like below)
     session     optional      pam_mkhomedir.so debug
     

  4. Configure system-auth.

     # cat /etc/pam.d/system-auth |grep optional
     (Change the line that has the keyword "optional" like below)
     session     optional      pam_mkhomedir.so debug
     

  5. Edit /etc/sysconfig/autofs and set：

     OPTIONS="--debug"
     

• Test.

  1. Create a user test in machineB.

     # useradd test 
     

  2. Delete user test home directory.

     # rm -rf /home/test
     

  3. SSH to machineB from machineC.

     # ssh test@<machineB-IP>
     

  4. If it comes out and show like this:

     $ ssh test@<machineB-IP>
     test@<machineB-IP>'s password: 
     Creating directory '/home/test'
     Last login: <time> from <IP-address>
     NFS autofs/home builder