pam_mkhomedir.so  [
        silent
      ] [
        debug
      ] [
        umask=mode
      ] [
        skel=skeldir
      ]
      The pam_mkhomedir PAM module will create a users home directory
      if it does not exist when the session begins. This allows users
      to be present in central database (such as NIS, kerberos or LDAP)
      without using a distributed file system or pre-creating a large
      number of directories. The skeleton directory (usually
      /etc/skel/) is used to copy default files
      and also sets a umask for the creation.
    
The new users home directory will not be removed after logout of the user.
Don't print informative messages.
Turns on debugging via syslog(3).
            The file mode creation mask is set to
            mask. The default value of mask
            is 0022. If this option is not specified, then the permissions
            of created user home directory  is set to the value of
            HOME_MODE configuration item from
            /etc/login.defs. If there is no such
            configuration item then the value is computed from the
            value of UMASK in the same file. If
            there is no such configuration option either the default
            value of 0755 is used for the mode.
          
            Indicate an alternative skel directory
            to override the default /etc/skel.
          
Memory buffer error.
Not enough permissions to create the new directory or read the skel directory.
User not known to the underlying authentication module.
Environment variables were set.
A sample /etc/pam.d/login file:
  auth       requisite   pam_securetty.so
  auth       sufficient  pam_ldap.so
  auth       required    pam_unix.so
  auth       required    pam_nologin.so
  account    sufficient  pam_ldap.so
  account    required    pam_unix.so
  password   required    pam_unix.so
  session    required    pam_mkhomedir.so skel=/etc/skel/ umask=0022
  session    required    pam_unix.so
  session    optional    pam_lastlog.so
  session    optional    pam_mail.so standard