Warning: log write time 520ms, size 1KB

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Warning: log write time 520ms, size 1KB

 今天登录数据库检查日志，发现有如下错误：
 more bb2_lgwr_6972.trc
 1、发现错误
 *** SERVICE NAME:() 2012-04-10 02:00:18.034
 *** SESSION ID:(1321.1) 2012-04-10 02:00:18.034
 Maximum redo generation record size = 156160 bytes
 Maximum redo generation change vector size = 150676 bytes
 *** 2012-04-20 10:00:51.735
 Warning: log write time 520ms, size 1KB
 *** 2012-04-20 10:12:33.692
 Warning: log write time 500ms, size 1KB
 *** 2012-04-22 04:09:57.617
 
Warning: log write time 3990ms, size 2KB
 

2、Metalink描述[ID 601316.1]
 Changes
 The problem surfaced after upgrading to 10.2.0.4.
 Cause
 The above warning messages has been introduced in 10.2.0.4 patchset. This warning message will be generated only if the log write time is more than 500 ms and it will be written to the lgwr trace file .
 Solution
 
These messages are very much expected in 10.2.0.4 database in case the log write is more than 500 ms. This is a warning which means that the write process is not as fast as it intented to be .So probably you need to check if the disk is slow or not or for any potential OS causes. If everything looks fine at the hardware level or OS level then you can safely ignore these messages. The trace file can easily be deleted or truncated.
 

3、网上解决方案
 the error may be suppressed by setting Event 10468 level 4.
 alter system set events ’10468 trace name context level 4′;
 取消该trace命令为：
 ALTER SYSTEM SET EVENTS ’10468 trace name context off’;
 

这些信息提示，数据库的日志写出现较长的等待，超过500ms的写出会被记录，一般来说是ＩＯ存在问题，写出缓慢所致。
 如果确认I/O没有问题，那么此信息可以忽略！