warning: aiowait timed out 2 times tue aug 26 15:33:32 2003 warning: aiowait timed out 2 times tue aug 26 15:33:34 2003 warning: aiowait timed out 2 times tue aug 26 15:33:36 2003 warning: aiowait timed out 2 times tue aug 26 15:33:38 2003 warning: aiowait timed out 2 times tue aug 26 15:33:43 2003 warning: aiowait timed out 1 times tue aug 26 15:33:46 2003 warning: aiowait timed out 1 times tue aug 26 15:33:49 2003 warning: aiowait timed out 1 times tue aug 26 15:33:51 2003 warning: aiowait timed out 1 times tue aug 26 15:33:52 2003 warning: aiowait timed out 1 times tue aug 26 15:33:53 2003 warning: aiowait timed out 1 times .............
我们知道在sun的某些版本上异步io存在问题 而异步io缺省是打开的
sql> show parameter disk_a
name type value ------------------------------------ ----------- ------------------------------ disk_asynch_io boolean true
针对此问题，我们停用了数据库的异步io写入。
2.共享内存问题
alert文件中还记录了以下错误信息:
tue aug 26 21:37:40 2003 warning: einval creating segment of size 0x0000000190400000 fix shm parameters in /etc/system or equivalent
该信息说明内核参数设置过小或者和sga不匹配
我们检查system配置文件
$ cat /etc/system ....................... set shmsys:shminfo_shmmax=4096000000 set shmsys:shminfo_shmmin=1 set shmsys:shminfo_shmmni=200 set shmsys:shminfo_shmseg=200 set semsys:seminfo_semmap=1024 set semsys:seminfo_semmni=2048 set semsys:seminfo_semmns=2048 set semsys:seminfo_semmnu=2048 set semsys:seminfo_semume=200 set semsys:seminfo_semmsl=2048
我们发现最大共享内存设置仅有4g
3.检查sga设置
sql*plus: release 9.2.0.3.0 - production on 星期二 8月 26 21:46:35 2003
copyright (c) 1982, 2002, oracle corporation. all rights reserved.
connected to: oracle9i enterprise edition release 9.2.0.3.0 - 64bit production with the partitioning, olap and oracle data mining options jserver release 9.2.0.3.0 - production
sql> show sga
total system global area 6695660272 bytes fixed size 740080 bytes variable size 2399141888 bytes database buffers 4294967296 bytes redo buffers 811008 bytes
我们发现sga设置接近7g，这也就是步骤2中错误提示出现的原因
4.交换区问题
我们用top工具检查系统运行状况
# /usr/local/bin/top
last pid: 16899; load averages: 0.82, 0.81, 0.83 21:49:05 1230 processes:1228 sleeping, 1 running, 1 on cpu cpu states: 50.1% idle, 7.4% user, 8.6% kernel, 33.9% iowait, 0.0% swap memory: 8192m real, 118m free, 12g swap in use, 11g swap free
