最近，我在我们新购买的服务器上安装了 Ubuntu-server 12.04.2 LTS。它运行良好，直到今天早上它自动重启。并且所有正在运行的程序都丢失了。为什么会自动重启？是硬件问题吗？我已经查看了很长时间的系统日志，但找不到有用的东西？任何身体都可以帮忙吗？
它在 6 点 42 分左右重新启动。这是来自 /var/log 的一些日志：
/var/日志/
May 31 06:42:04 iipl2013 sshd[1174]: Server listening on :: port 22.
May 31 06:42:04 iipl2013 sshd[1174]: Server listening on 0.0.0.0 port 22.
May 31 06:42:04 iipl2013 sshd[1174]: Received signal 15; terminating.
May 31 06:42:04 iipl2013 sshd[1499]: Server listening on 0.0.0.0 port 22.
May 31 06:42:04 iipl2013 sshd[1499]: Server listening on :: port 22.
May 31 06:42:06 iipl2013 lightdm: pam_unix(lightdm:session): session opened for user lightdm by (uid=0)
May 31 06:42:06 iipl2013 lightdm: pam_ck_connector(lightdm:session): nox11 mode, ignoring PAM_TTY :0
May 31 06:42:08 iipl2013 lightdm: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "all"
May 31 06:42:08 iipl2013 dbus[1187]: [system] Rejected send message, 2 matched rules; type="method_call", sender=":1.23" (uid=111 pid=2539 comm="/usr/lib/indicator-datetime/indicator-datetime-ser") interface="org.freedesktop.DBus.Properties" member="GetAll" error name="(unset)" requested_reply="0" destination=":1.14" (uid=0 pid=1977 comm="/usr/sbin/console-kit-daemon --no-daemon ")
May 31 07:17:01 iipl2013 CRON[3348]: pam_unix(cron:session): session opened for user root by (uid=0)
May 31 07:17:01 iipl2013 CRON[3348]: pam_unix(cron:session): session closed for user root
/var/log/系统日志
May 31 06:47:05 iipl2013 anacron[1827]: Job `cron.daily' started
May 31 06:47:05 iipl2013 anacron[3044]: Updated timestamp for job `cron.daily' to 2013-05-31
May 31 06:47:11 iipl2013 kernel: [ 324.097505] audit_printk_skb: 69 callbacks suppressed
May 31 06:47:11 iipl2013 kernel: [ 324.097512] type=1400 audit(1369954031.407:35): apparmor="DENIED" operation="capable" parent=1 profile="/usr/sbin/cupsd" pid=1229 comm="cupsd" pid=1229 comm="cupsd" capability=36 capname="block_suspend"
May 31 07:00:02 iipl2013 kernel: [ 1093.560934] type=1400 audit(1369954802.071:36): apparmor="DENIED" operation="capable" parent=1 profile="/usr/sbin/cupsd" pid=1229 comm="cupsd" pid=1229 comm="cupsd" capability=36 capname="block_suspend"
重启是否受“cups”、“lightdm”或“xrdp”的影响？有任何想法吗？