Keep the default setting and leave the check box selected, as shown in Figure 5-5. Figure 5-5 Create an NFS export wizard: Port Security definition Enabling this option prevents root users, from the NFS client systems, from having root  privileges on the NFS export that are provided by ProtecTIER. If you do not enable root  squash, any root user of a remote system might delete any user data on the mounted NFS  export because root can delete any data of foreign users.  To prevent this action, the  root squash  option maps the root user ID 0 (UID) and group ID 0  (GID) to a customized UID. By doing this task, the remote root user cannot delete or modify  any other data than the one that is created with the customized UID. Typically, the root squash  function by default maps the UID to  nfsnobody , but in the ProtecTIER implementation, the UID  of that user is higher than the value that you are allowed to enter in the wizard’s field.  Alternatively, the  no_root_squash  option turns off root squashing.  Root squash  Chapter 5. ProtecTIER File System Interface: General introduction  73