使用CentOS系统的时候，经常会遇到系统日志文件非常大的情况，如果直接删除，会导致日志错误，不再生成日志，这时，我们可以使用下面的方法清空日志。
CentOS 6系统
cat/dev/null>/var/log/boot.log cat/dev/null>/var/log/btmp cat/dev/null>/var/log/cron cat/dev/null>/var/log/dmesg cat/dev/null>/var/log/dracut.log cat/dev/null>/var/log/lastlog cat/dev/null>/var/log/maillog cat/dev/null>/var/log/messages cat/dev/null>/var/log/secure cat/dev/null>/var/log/spooler cat/dev/null>/var/log/tallylog cat/dev/null>/var/log/wtmp cat/dev/null>/var/log/yum.log
CentOS 7系统
cat/dev/null>/var/log/boot.log cat/dev/null>/var/log/btmp cat/dev/null>/var/log/cron cat/dev/null>/var/log/dmesg cat/dev/null>/var/log/firewalld cat/dev/null>/var/log/grubby cat/dev/null>/var/log/lastlog cat/dev/null>/var/log/mail.info cat/dev/null>/var/log/maillog cat/dev/null>/var/log/messages cat/dev/null>/var/log/secure cat/dev/null>/var/log/spooler cat/dev/null>/var/log/syslog cat/dev/null>/var/log/tallylog cat/dev/null>/var/log/wpa_supplicant.log cat/dev/null>/var/log/wtmp cat/dev/null>/var/log/yum.log
