ORA-27125: unable to create shared memory segment

案例環境：

操做系統環境 ： Oracle Linux Server release 5.7 x86_64

數據庫版本     ： Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - 64bi

在安裝Oracle安裝過程當中，dbca 建instance的，遇到以下錯誤:ORA-27125: unable to create shared memory segment

分析解決：

之前遇到安裝ORACLE成功後，啓動過程當中遇到ORA-27125錯誤, 也在博客ORA-27125: unable to create shared memory segment和博客ORA-27125裏面記錄過，因而按照解決方法作了以下操做:

   1: [root@DB-Server cdrom]# id oracle

   2:  

   3: uid=502(oracle) gid=502(oinstall) groups=502(oinstall),503(dba)

   4:  

   5: [root@DB-Server cdrom]# more /proc/sys/vm/hugetlb_shm_group

   6:  

   7: 0

   8:  

   9: [root@DB-Server cdrom]# echo 502 >/proc/sys/vm/hugetlb_shm_group

  10:  

  11: [root@DB-Server cdrom]# 

而後在/etc/sysctl.conf 裏面添加參數vm.hugetlb_shm_group = 502，就能夠在下次啓動時不報ORA-27125錯誤。

過後跟老大聊了一下這個錯誤，老大說他之前也使用這個版本的操做系統和數據庫安裝鏡像（咱們使用一樣的操做系統、數據庫安裝鏡像文件），可是沒有遇到過這類問題。我也看過eygel的博客http://www.eygle.com/archives/2011/12/hugepageshugetl.html 以及David的博客http://blog.csdn.net/tianlesoftware/article/details/7309046，基本上都是涉及hugetlb_shm_group，通過一番探索，老大發了Metalink上的一個連接給我：https://support.oracle.com/epmos/faces/BugDisplay?_afrLoop=446607573886554&id=4726024&_afrWindowMode=0&_adf.ctrl-state=k6an80rhq_4   以下所示：

Hdr: 4726024 10.2.0.1 RDBMS 10.2.0.1 OSD PRODID-5 PORTID-226 ORA-27125

Abstract: GETTING ORA-27125 WHEN TRYING TO STARTUP INSTANCE

*** 11/08/05 06:47 pm ***

TAR:

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15683356.6

PROBLEM:

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Customer installed 10.2.0.1  on SuSe SLES9

Get the following error when trying to startup instance either using sqlplus or dbca

ORA-27125 unable to create shared memory segment

Linux-86_64 Error: 1 Operation not permitted

DIAGNOSTIC ANALYSIS:

--------------------

Looks like customer is runinng into bug Bug 3681720.  This bug is closed as

dup of 3520770 which indicated problem is fixed in 10.2.

But customer is still encountering this error.

WORKAROUND:

-----------

Set disable_cap_mlock to 1

$ echo 1 > /proc/sys/vm/disable_cap_mlock

RELATED BUGS:

-------------

3681720

3520770

REPRODUCIBILITY:

----------------

TEST CASE:

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STACK TRACE:

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SUPPORTING INFORMATION:

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24 HOUR CONTACT INFORMATION FOR P1 BUGS:

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DIAL-IN INFORMATION:

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IMPACT DATE:

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因而我打上10.0.2.4.0的補丁後。而後在/etc/sysctl.conf 將參數vm.hugetlb_shm_group = 502註釋後，從新關閉、啓動數據庫，測試結果顯示，ORA-27125錯誤不見了。顯然這是在Linux x86-64平臺上，ORACLE 10.2.0.1的一個Bug來的。至於老大爲何沒有碰到這個錯誤，他解釋是安裝完成後，直接打補丁升級，而後啓動數據庫。可是很奇怪安裝過程當中也沒有碰到這個錯誤，而我就屢次碰到了。