HP 서버(Red Hat 설치)가 갑자기 죽습니다. 로그를 보시고 조언 부탁드릴께요~

서버 : HP 서버 (정확한 모델 명은 모르겠네요.. 나중에 모델명 업뎃 할께요~)
OS :
Red Hat Enterprise Linux ES release 4 (Nahant Update 4)
Kernel 2.6.9-42.EL on an ia64

를 사용 중입니다.

이 녀석이 일주일에 한번꼴로 꺼져버립니다. 아침에 출근해보면 꺼져 있더라고요..한 1주일에 1번꼴로여..

다음은 /var/log 폴더에 있는 messages 로그 입니다.

ul 19 04:02:15 SAlinux syslogd 1.4.1: restart.
Jul 20 08:08:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed -2 Celsius to 39 Celsius since last report
Jul 20 09:08:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed -2 Celsius to 37 Celsius since last report
Jul 20 18:38:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed 2 Celsius to 39 Celsius since last report
Jul 20 22:08:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed 2 Celsius to 41 Celsius since last report
Jul 21 07:38:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed -2 Celsius to 39 Celsius since last report
Jul 21 09:08:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed -2 Celsius to 37 Celsius since last report
Jul 21 19:08:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed 2 Celsius to 39 Celsius since last report
Jul 22 09:08:48 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed -2 Celsius to 37 Celsius since last report
Jul 22 19:08:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed 2 Celsius to 39 Celsius since last report
Jul 23 06:08:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed 2 Celsius to 41 Celsius since last report
Jul 23 07:38:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed -2 Celsius to 39 Celsius since last report
Jul 23 09:38:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed -2 Celsius to 37 Celsius since last report
Jul 23 19:08:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed 2 Celsius to 39 Celsius since last report
Jul 24 08:38:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed -2 Celsius to 37 Celsius since last report
Jul 24 11:12:32 SAlinux remote(pam_unix)[31631]: check pass; user unknown
Jul 24 11:12:32 SAlinux remote(pam_unix)[31631]: authentication failure; logname= uid=0 euid=0 tty=pts/1 ruser= rhost=172.22.19.123
Jul 24 11:12:34 SAlinux login[31631]: FAILED LOGIN 1 FROM 172.22.19.123 FOR lg, Authentication failure
Jul 24 11:12:39 SAlinux remote(pam_unix)[31631]: session opened for user user01 by (uid=0)
Jul 24 11:12:39 SAlinux -- user01[31631]: LOGIN ON pts/1 BY user01 FROM 172.22.19.123
Jul 24 11:12:49 SAlinux su(pam_unix)[31660]: authentication failure; logname=user01 uid=503 euid=0 tty=pts/1 ruser=user01 rhost= user=root
Jul 24 11:12:59 SAlinux su(pam_unix)[31661]: authentication failure; logname=user01 uid=503 euid=0 tty=pts/1 ruser=user01 rhost= user=root
Jul 24 11:13:08 SAlinux su(pam_unix)[31662]: session opened for user root by user01(uid=503)
Jul 24 17:50:01 SAlinux su(pam_unix)[31662]: session closed for user root
Jul 24 17:50:03 SAlinux remote(pam_unix)[31631]: session closed for user user01
Jul 24 19:08:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed 2 Celsius to 39 Celsius since last report
Jul 25 01:46:35 SAlinux kernel: tg3: eth0: Link is down.
Jul 25 03:01:04 SAlinux kernel: tg3: eth0: Link is up at 1000 Mbps, full duplex.
Jul 25 03:01:04 SAlinux kernel: tg3: eth0: Flow control is off for TX and off for RX.
Jul 26 04:02:06 SAlinux cups: cupsd shutdown succeeded
Jul 26 04:02:07 SAlinux cups: cupsd startup succeeded
Jul 26 04:02:15 SAlinux syslogd 1.4.1: restart.
Jul 26 11:08:47 SAlinux smartd[3105]: Device: /dev/sda, Temperature changed 2 Celsius to 41 Celsius since last report
Jul 27 11:11:24 SAlinux syslogd 1.4.1: restart. ----------> 이날 출근해보니 서버가 꺼져 있길래 제가 수동으로 ON 하였습니다.
Jul 27 11:11:24 SAlinux syslog: syslogd startup succeeded

도대체 뭐가 문제일까요..?

이 로그 말고 다른 로그를 봐야하나요? 아시는 분 조언 부탁드릴께요~ 답답하기도 하고 약오르기도 하고 참 거시게 하네요.. ;;

걍 제가 잠정적으로 내린 결론은 일단.. 온도가 아닐까..? 하고 있는데...;; 이게 맞다면 어떻게 확인을 해봐야 할지도 참 막막하고...흠..;;