谁能告诉我为什么我的Ubuntu服务器崩溃了？

我的Ubuntu服务器版本11.10几天前在没有任何理由的情况下下了半夜。 现在我想知道什么是问题。

这里是syslog的一部分，我无法理解一个单词。 任何人都可以帮我指出这个问题吗？

服务器停机时间在23:17:01和07:41:43之间，直到我们重新启动它的硬件。

Jul 15 22:55:02 my-webserver CRON[4879]: (CRON) info (No MTA installed, discarding output) Jul 15 23:00:01 my-webserver CRON[5576]: (munin) CMD (/usr/bin/munin-cron) Jul 15 23:00:01 my-webserver CRON[5578]: (root) CMD (if [ -x /etc/munin/plugins/apt_all ]; then /etc/munin/plugins/apt_all update 7200 12 >/dev/null; elif [ -x /etc/munin/plugins/apt ]; then /etc/munin/plugins/apt update 7200 12 >/dev/null; fi) Jul 15 23:00:01 my-webserver CRON[5577]: (munin) CMD (if [ -x /usr/bin/munin-cron ]; then /usr/bin/munin-cron; fi) Jul 15 23:00:02 my-webserver CRON[5575]: (CRON) error (grandchild #5576 failed with exit status 1) Jul 15 23:00:02 my-webserver CRON[5575]: (CRON) info (No MTA installed, discarding output) Jul 15 23:05:01 my-webserver CRON[6229]: (munin) CMD (if [ -x /usr/bin/munin-cron ]; then /usr/bin/munin-cron; fi) Jul 15 23:05:01 my-webserver CRON[6230]: (munin) CMD (/usr/bin/munin-cron) Jul 15 23:05:01 my-webserver CRON[6231]: (root) CMD (if [ -x /etc/munin/plugins/apt_all ]; then /etc/munin/plugins/apt_all update 7200 12 >/dev/null; elif [ -x /etc/munin/plugins/apt ]; then /etc/munin/plugins/apt update 7200 12 >/dev/null; fi) Jul 15 23:05:01 my-webserver CRON[6226]: (CRON) error (grandchild #6229 failed with exit status 1) Jul 15 23:05:01 my-webserver CRON[6226]: (CRON) info (No MTA installed, discarding output) Jul 15 23:09:01 my-webserver CRON[6838]: (root) CMD ( [ -x /usr/lib/php5/maxlifetime ] && [ -d /var/lib/php5 ] && find /var/lib/php5/ -depth -mindepth 1 -maxdepth 1 -type f -cmin +$(/usr/lib/php5/maxlifetime) ! -execdir fuser -s {} 2>/dev/null \; -delete) Jul 15 23:10:01 my-webserver CRON[8404]: (munin) CMD (if [ -x /usr/bin/munin-cron ]; then /usr/bin/munin-cron; fi) Jul 15 23:10:01 my-webserver CRON[8405]: (root) CMD (if [ -x /etc/munin/plugins/apt_all ]; then /etc/munin/plugins/apt_all update 7200 12 >/dev/null; elif [ -x /etc/munin/plugins/apt ]; then /etc/munin/plugins/apt update 7200 12 >/dev/null; fi) Jul 15 23:10:01 my-webserver CRON[8407]: (munin) CMD (/usr/bin/munin-cron) Jul 15 23:10:01 my-webserver CRON[8401]: (CRON) error (grandchild #8404 failed with exit status 1) Jul 15 23:10:01 my-webserver CRON[8401]: (CRON) info (No MTA installed, discarding output) Jul 15 23:15:01 my-webserver CRON[9036]: (munin) CMD (if [ -x /usr/bin/munin-cron ]; then /usr/bin/munin-cron; fi) Jul 15 23:15:01 my-webserver CRON[9035]: (munin) CMD (/usr/bin/munin-cron) Jul 15 23:15:01 my-webserver CRON[9041]: (root) CMD (if [ -x /etc/munin/plugins/apt_all ]; then /etc/munin/plugins/apt_all update 7200 12 >/dev/null; elif [ -x /etc/munin/plugins/apt ]; then /etc/munin/plugins/apt update 7200 12 >/dev/null; fi) Jul 15 23:15:01 my-webserver CRON[9034]: (CRON) error (grandchild #9035 failed with exit status 1) Jul 15 23:15:01 my-webserver CRON[9034]: (CRON) info (No MTA installed, discarding output) Jul 15 23:17:01 my-webserver CRON[9544]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly) Jul 16 07:41:43 my-webserver kernel: imklog 5.8.1, log source = /proc/kmsg started. Jul 16 07:41:43 my-webserver rsyslogd: [origin software="rsyslogd" swVersion="5.8.1" x-pid="783" x-info="http://www.rsyslog.com"] start Jul 16 07:41:43 my-webserver rsyslogd: rsyslogd's groupid changed to 103 Jul 16 07:41:43 my-webserver rsyslogd: rsyslogd's userid changed to 101 Jul 16 07:41:43 my-webserver rsyslogd-2039: Could no open output pipe '/dev/xconsole' [try http://www.rsyslog.com/e/2039 ] Jul 16 07:41:43 my-webserver kernel: [ 0.000000] Initializing cgroup subsys cpuset Jul 16 07:41:43 my-webserver kernel: [ 0.000000] Initializing cgroup subsys cpu Jul 16 07:41:43 my-webserver kernel: [ 0.000000] Linux version 3.0.0-12-server (buildd@crested) (gcc version 4.6.1 (Ubuntu/Linaro 4.6.1-9ubuntu3) ) #20-Ubuntu SMP Fri Oct 7 16:36:30 UTC 2011 (Ubuntu 3.0.0-12.20-server 3.0.4)