ORA-27090 故障一例

青旅半醒 2022-08-12 16:14 591阅读 0赞

最近的alert日志中碰到了ORA-27090的错误信息，其错误提示为Unable to reserve kernel resources for asynchronous disk I/O。根据这个提示来看是跟异步I/O相关的内核参数问题。下面是这个问题的描述与解决。

1、故障错误信息  
Wed Sep 10 09:58:17 CST 2014  
Errors in file /u01/app/oracle/admin/orclls/bdump/orclls\_p000\_47020.trc:  
ORA-27090: Unable to reserve kernel resources for asynchronous disk I/O  
Linux-x86\_64 Error: 2: No such file or directory  
Additional information: 3  
Additional information: 128  
Additional information: 65536  
Wed Sep 10 09:58:17 CST 2014  
Errors in file /u01/app/oracle/admin/orclls/bdump/orclls\_p002\_47024.trc:  
ORA-27090: Unable to reserve kernel resources for asynchronous disk I/O  
Linux-x86\_64 Error: 2: No such file or directory  
Additional information: 3  
Additional information: 128  
Additional information: 65536

2、故障分析  
\#调用oerr，没有获得比较有价值的信息，如下：  
suse11b:oracle:orcl102 > oerr ora 27090  
27090, 00000, "Unable to reserve kernel resources for asynchronous disk I/O"  
// \*Cause:  The system call to reserve kernel resources for asynchronous I/O  
//          has failed.  
// \*Action: Check errno

\#进一步查看trace文件，注，当前数据库版本为10.2.0.5，OS为suse 11 sp3  
suse11a:oracle:orcl101 > more /u01/app/oracle/admin/orclls/bdump/orclls\_p002\_47024.trc  
/u01/app/oracle/admin/orclls/bdump/orclls\_p002\_47024.trc  
Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bit Production  
With the Partitioning, Real Application Clusters, OLAP, Data Mining  
and Real Application Testing options  
ORACLE\_HOME = /u01/app/oracle/product/10.2/db\_1  
System name:    Linux  
Node name:      suse11a  
Release:        3.0.76-0.11-default  
Version:        \#1 SMP Fri Jun 14 08:21:43 UTC 2013 (ccab990)  
Machine:        x86\_64  
Instance name: orclls  
Redo thread mounted by this instance: 1  
Oracle process number: 35  
Unix process pid: 47024, image: oracle@suse11a (P002)

\*\*\* SERVICE NAME:() 2014-09-10 09:58:17.159  
\*\*\* SESSION ID:(1072.1) 2014-09-10 09:58:17.159  
\*\*\* 2014-09-10 09:58:17.159  
KCRP: blocks claimed = 0, eliminated = 0  
\----- Recovery Hash Table Statistics ---------  
Hash table buckets = 32768  
Longest hash chain = 0  
Average hash chain = 0/0 = 0.0  
Max compares per lookup = 0  
Avg compares per lookup = 0/0 = 0.0  
\----------------------------------------------  
ORA-27090: Unable to reserve kernel resources for asynchronous disk I/O  
Linux-x86\_64 Error: 2: No such file or directory  
Additional information: 3  
Additional information: 128  
Additional information: 65536  
\----- Recovery Hash Table Statistics ---------  
Hash table buckets = 32768  
Longest hash chain = 0  
Average hash chain = 0/0 = 0.0  
Max compares per lookup = 0  
Avg compares per lookup = 0/0 = 0.0  
\----------------------------------------------  
\#从trace文件中也没有获得比较有价值的信息

3、故障解决  
\#根据ORA-27090: MESSAGE 27090 NOT FOUND; (文档 ID 579108.1)文档，我们修改内核参数fs.aio-max-nr  
\#由于此数据库为RAC环境下，因此同时调整了2个节点，以下为调整后的情形。  
suse11a:~ \# grep max-nr /etc/sysctl.conf  
\#fs.aio-max-nr = 1048576  
fs.aio-max-nr = 3145728

suse11b:~ \# grep max-nr /etc/sysctl.conf  
\#aio-max-nr = 1048576  
fs.aio-max-nr = 3145728

suse11a:~ \# sysctl -p  
suse11b:~ \# sysctl -p

\#配置完毕后可以通过cluvy校验  
\#几日后观察alert日志，未发现该类错误。

Check: Kernel parameter for "aio-max-nr"  
  Node Name         Current       Configured    Required      Status        Comment      
  ----------------  ------------  ------------  ------------  ------------  ------------  
  suse11a           3145728       3145728       1048576       passed           
  suse11b           3145728       3145728       1048576       passed           
Result: Kernel parameter check passed for "aio-max-nr"

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