If using earlier versions, use "star" to backup and restore files with extended attributes. SELinux and ACLs use these Extended Attributes to store the security contexts and access control lists respectively.
Tar has now been rebuilt in RedHat 5 and added support for Extended Attributes.
--selinux Archive the SELinux attributes of the files and directories --acls Archive the ACL attributes of files and directories --xattrs Archive all Extended Attributes of files and directories. This includes both SELinux and ACL attributes, as well as any other xattr.