Is this normal ?May 8 23:45:26 tiger crond(pam_unix)[27273]: session closed for user root
May 9 00:00:01 tiger crond(pam_unix)[27439]: session opened for user root by (uid=0)
May 9 00:00:01 tiger su(pam_unix)[27441]: session opened for user qmailr by (uid=0)
May 9 00:00:12 tiger su(pam_unix)[27441]: session closed for user qmailr
May 9 00:00:12 tiger crond(pam_unix)[27439]: session closed for user root
May 9 00:01:01 tiger crond(pam_unix)[27475]: session opened for user root by (uid=0)
May 9 00:01:01 tiger crond(pam_unix)[27475]: session closed for user root
May 9 00:15:01 tiger crond(pam_unix)[27573]: session opened for user root by (uid=0)
May 9 00:15:01 tiger su(pam_unix)[27575]: session opened for user qmailr by (uid=0)
May 9 00:15:12 tiger su(pam_unix)[27575]: session closed for user qmailr
May 9 00:15:12 tiger crond(pam_unix)[27573]: session closed for user root
May 9 00:30:01 tiger crond(pam_unix)[27721]: session opened for user root by (uid=0)
May 9 00:30:01 tiger su(pam_unix)[27723]: session opened for user qmailr by (uid=0)
May 9 00:30:12 tiger su(pam_unix)[27723]: session closed for user qmailr
May 9 00:30:12 tiger crond(pam_unix)[27721]: session closed for user root
May 9 00:37:01 tiger crond(pam_unix)[27796]: session opened for user root by (uid=0)
May 9 00:37:02 tiger crond(pam_unix)[27796]: session closed for user root
May 9 00:45:01 tiger crond(pam_unix)[27875]: session opened for user root by (uid=0)
May 9 00:45:01 tiger su(pam_unix)[27877]: session opened for user qmailr by (uid=0)
May 9 00:45:12 tiger su(pam_unix)[27877]: session closed for user qmailr
May 9 00:45:12 tiger crond(pam_unix)[27875]: session closed for user root
May 9 00:58:01 tiger crond(pam_unix)[27985]: session opened for user root by (uid=0)
May 9 01:00:01 tiger crond(pam_unix)[28008]: session opened for user root by (uid=0)
May 9 01:00:01 tiger su(pam_unix)[28010]: session opened for user qmailr by (uid=0)
May 9 01:00:24 tiger su(pam_unix)[28010]: session closed for user qmailr
May 9 01:00:24 tiger crond(pam_unix)[28008]: session closed for user root
May 9 01:01:01 tiger crond(pam_unix)[28080]: session opened for user root by (uid=0)
May 9 01:01:01 tiger crond(pam_unix)[28080]: session closed for user root
May 9 01:15:02 tiger crond(pam_unix)[28186]: session opened for user root by (uid=0)
May 9 01:15:02 tiger su(pam_unix)[28190]: session opened for user qmailr by (uid=0)
May 9 01:15:14 tiger su(pam_unix)[28190]: session closed for user qmailr
May 9 01:15:14 tiger crond(pam_unix)[28186]: session closed for user root
May 9 01:30:02 tiger crond(pam_unix)[28357]: session opened for user root by (uid=0)
May 9 01:30:02 tiger su(pam_unix)[28359]: session opened for user qmailr by (uid=0)
May 9 01:30:13 tiger su(pam_unix)[28359]: session closed for user qmailr
May 9 01:30:13 tiger crond(pam_unix)[28357]: session closed for user root
May 9 01:45:01 tiger crond(pam_unix)[28510]: session opened for user root by (uid=0)
May 9 01:45:01 tiger su(pam_unix)[28516]: session opened for user qmailr by (uid=0)
May 9 01:45:36 tiger su(pam_unix)[28516]: session closed for user qmailr
May 9 01:45:36 tiger crond(pam_unix)[28510]: session closed for user root
May 9 02:00:01 tiger crond(pam_unix)[28687]: session opened for user root by (uid=0)
May 9 02:00:01 tiger su(pam_unix)[28693]: session opened for user qmailr by (uid=0)
May 9 02:00:13 tiger su(pam_unix)[28693]: session closed for user qmailr
May 9 02:00:13 tiger crond(pam_unix)[28687]: session closed for user root
May 9 02:01:01 tiger crond(pam_unix)[28751]: session opened for user root by (uid=0)