剛幫忙解掉的問題。
某台建立在 OpenVZ 的 Ubuntu 的 rsyslog daemon process 瘋狂佔用 CPU resource。
log 看到的狀況是這樣：
... Dec 14 06:25:13 Linux rsyslogd-2177: rsyslogd[internal_messages]: 1134916 messages lost due to rate-limiting Dec 14 06:25:13 Linux rsyslogd: imklog: error reading kernel log - shutting down: Bad file descriptor Dec 14 06:25:13 Linux rsyslogd: message repeated 498 times: [imklog: error reading kernel log - shutting down: Bad file descriptor] Dec 14 06:25:19 Linux rsyslogd-2177: rsyslogd[internal_messages]: 1114295 messages lost due to rate-limiting Dec 14 06:25:19 Linux rsyslogd: imklog: error reading kernel log - shutting down: Bad file descriptor Dec 14 06:25:19 Linux rsyslogd: message repeated 498 times: [imklog: error reading kernel log - shutting down: Bad file descriptor] Dec 14 06:25:25 Linux rsyslogd-2177: rsyslogd[internal_messages]: 1805432 messages lost due to rate-limiting Dec 14 06:25:25 Linux rsyslogd: imklog: error reading kernel log - shutting down: Bad file descriptor Dec 14 06:25:25 Linux rsyslogd: message repeated 498 times: [imklog: error reading kernel log - shutting down: Bad file descriptor] ...
把 /etc/rsyslog.conf 下列這行註解掉，重新啟動 rsyslog 就搞定了… 
$ModLoad imklog # provides kernel logging support