LOG日志级别

说明：控制错误日志的详细程度

语法：Log Level级别

默认值：Log Level warn

Level	Description	Example
emerg	Emergencies - system is unusable 紧急 - 系统无法使用	Child cannot open lock file. Exiting
alert	Action must be taken immediately 必须立即采取措施	getpwuid: couldn't determine user name from uid
crit	Critical Conditions   致命情况	socket: Failed to get a socket, exiting child
error	Error conditions 错误情况	Premature end of script headers
warn	Warning conditions 警告情况	child process 1234 did not exit, sending another SIGHUP
notice	Normal but significant condition 一般重要情况	httpd: caught SIGBUS, attempting to dump core in ..."
info	Informational 普通信息	Server seems busy, (you may need to increase StartServers, or Min/MaxSpareServers)..."
debug	Debug-level messages 出错级别信息	Opening config file ..."
备注: 1）When a particular level is specified, messages from all other levels of higher significance will be reported as well. （当指定了特定级别时，所有级别高于它的信息也会同时报告） 2）E.g.when LogLevel info is specified, then messages with log levels of notice and warn will also be posted.（比如说，当指定了LogLevel info时，所有 notice和warn级别的信息也会被记录） 3）Using a level of at least crit is recommended.（建议至少要使用crit级别）

source:  http://cjhust.blog.163.com/blog/static/175827157201172025919798/