我有一个安装了Webmin和Virtualmin的CentOS 7 VPS。 我有这个服务器上的几个域以及邮件服务器（Postfix，Dovecot）。 有时我无法访问它（从webmin使用IP地址或SSH），直到我从我的提供商面板重新启动机器。 我怎样才能发现问题？ 我必须看什么日志？
这里输出“grep -i”杀死进程“/ var / log / messages”
Oct 2 13:08:32 server kernel: Killed process 2840 (mysqld) total-vm:1641792kB, anon-rss:20564kB, file-rss:0kB Oct 3 04:24:09 server kernel: Killed process 2874 (mysqld) total-vm:1637124kB, anon-rss:11628kB, file-rss:0kB Oct 3 05:16:05 server kernel: Killed process 26933 (sh) total-vm:11636kB, anon-rss:4kB, file-rss:140kB Oct 3 05:16:05 server kernel: Killed process 26884 (/usr/libexec/we) total-vm:165912kB, anon-rss:28kB, file-rss:132kB Oct 3 05:16:05 server kernel: Killed process 26753 (/usr/libexec/we) total-vm:161776kB, anon-rss:80kB, file-rss:16kB Oct 3 05:16:05 server kernel: Killed process 26852 (/usr/libexec/we) total-vm:132660kB, anon-rss:2476kB, file-rss:12kB Oct 3 05:16:05 server kernel: Killed process 26903 (/usr/libexec/we) total-vm:132656kB, anon-rss:1964kB, file-rss:12kB Oct 3 05:16:05 server kernel: Killed process 26715 (php-cgi) total-vm:486184kB, anon-rss:5772kB, file-rss:136kB Oct 3 05:16:05 server kernel: Killed process 26953 (sh) total-vm:11636kB, anon-rss:0kB, file-rss:4kB Oct 3 05:16:05 server kernel: Killed process 26749 (/usr/libexec/we) total-vm:113144kB, anon-rss:1444kB, file-rss:148kB Oct 3 05:16:05 server kernel: Killed process 26954 (sh) total-vm:11636kB, anon-rss:4kB, file-rss:0kB Oct 3 05:16:05 server kernel: Killed process 26795 (/usr/libexec/we) total-vm:113144kB, anon-rss:1132kB, file-rss:0kB Oct 3 05:16:05 server kernel: Killed process 27303 (mysqld) total-vm:288396kB, anon-rss:9340kB, file-rss:0kB Oct 3 05:16:05 server kernel: Killed process 27109 (php-cgi) total-vm:453836kB, anon-rss:2144kB, file-rss:20488kB Oct 3 05:16:05 server kernel: Killed process 27111 (php-cgi) total-vm:453836kB, anon-rss:2308kB, file-rss:20000kB Oct 3 05:16:05 server kernel: Killed process 26851 (/usr/libexec/we) total-vm:105188kB, anon-rss:2620kB, file-rss:4kB Oct 3 05:16:05 server kernel: Killed process 26898 (/usr/libexec/we) total-vm:105188kB, anon-rss:2660kB, file-rss:44kB Oct 3 05:34:26 server kernel: Killed process 27190 (php-cgi) total-vm:453836kB, anon-rss:2160kB, file-rss:20624kB Oct 3 05:57:53 server kernel: Killed process 27186 (php-cgi) total-vm:453836kB, anon-rss:2324kB, file-rss:20280kB Oct 3 06:00:46 server kernel: Killed process 27180 (php-cgi) total-vm:453836kB, anon-rss:2520kB, file-rss:20312kB Oct 3 06:02:00 server kernel: Killed process 27187 (php-cgi) total-vm:453836kB, anon-rss:2240kB, file-rss:20076kB Oct 3 06:04:16 server kernel: Killed process 2889 (named) total-vm:245060kB, anon-rss:512kB, file-rss:0kB Oct 3 06:11:19 server kernel: Killed process 26709 (php-cgi) total-vm:471000kB, anon-rss:2228kB, file-rss:380kB Oct 3 06:12:28 server kernel: Killed process 27308 (/usr/libexec/we) total-vm:96044kB, anon-rss:6292kB, file-rss:528kB Oct 3 06:12:48 server kernel: Killed process 26788 (php-cgi) total-vm:464152kB, anon-rss:1852kB, file-rss:908kB Oct 3 06:57:17 server kernel: Killed process 27465 (/usr/libexec/we) total-vm:102616kB, anon-rss:5608kB, file-rss:360kB Oct 3 07:32:00 server kernel: Killed process 27457 (/usr/libexec/we) total-vm:102620kB, anon-rss:5080kB, file-rss:380kB Oct 3 07:55:06 server kernel: Killed process 27474 (/usr/libexec/we) total-vm:102616kB, anon-rss:5156kB, file-rss:180kB 首先检查内存占用情况。 可能会有一些服务泄漏，所以内存消耗可能会随着时间而增加。
如果你没有准备好，请调整它。 有很好的howto：
http://www.thegeekstuff.com/2011/03/sar-examples/?utm_source=feedburner
看来你有内存泄漏。 首先检查你的日志。
grep -i 'killed process' /var/log/messages
然后你可以试试这个技巧来找出你记忆的过程。 将此命令添加为crontab任务：
ps aux | awk '{mem[$11]+=int($6/1024)}; {cpuper[$11]+=$3};{memper[$11]+=$4}; END {for (i in mem) {print cpuper[i]"% ",memper[i]"% ",mem[i]" MB ",i}}' | sort -k3nr | head -n 5 >> /tmp/memoryleak.log
现在你可以检查/var/log/memoryleak.log
除了sar之外，您还可以安装atop并configuration日志，以查找导致高CPU / RAM使用率的确切过程。