（轉）設置了RemoveIPC=yes 的RHEL7.2 會crash掉Oracle asm 實例和Oracle database實例

設置了RemoveIPC=yes 的RHEL7.2  會crash掉Oracle asm 實例和Oracle database實例，該問題也會在使用Shared Memory Segment (SHM) or Semaphores (SEM)的應用程序中發生。
來源於：
ALERT: Setting RemoveIPC=yes on Redhat 7.2 Crashes ASM and Database Instances as Well as Any Application That Uses a Shared Memory Segment (SHM) or Semaphores (SEM) (文檔 ID 2081410.1)

適用於：
Oracle Database - Standard Edition
Oracle Database - Enterprise Edition
Linux x86-64
Linux x86

描述：
在RHEL7.2中，systemd-logind 服務引入了一個新特性，該新特性是：當一個user 徹底退出os以後，remove掉全部的IPC objects。
該特性由/etc/systemd/logind.conf參數文件中RemoveIPC選項來控制。詳細請看man logind.conf(5)

在RHEL7.2中，RemoveIPC的默認值爲yes

所以，當最後一個oracle 或者Grid用戶退出時，操做系統會remove 掉這個user的shared memory segments and semaphores

因爲Oracle ASM 和database 使用 shared memory segments ，remove shared memory segments將會crash掉Oracle ASM and database  instances.

請參考Redhat bug 1264533  - https://bugzilla.redhat.com/show_bug.cgi?id=1264533

 

OCCURRENCE（不知道翻譯成什麼比較合適）
該問題影響使用the shared memory segments 和semaphores 的全部應用程序,所以，Oracle ASM 實例和Oracle Database 實例均受到影響。

Oracle Linux 7.2 經過在/etc/systemd/logind.conf配置文件中明確設置RemoveIPC爲no，Oracle Linux7.2 避免了該問題，
可是如果/etc/systemd/logind.conf文件是在os upgrade以前修改的，那麼yum/update將會寫一個正確的配置文件（RemoveIPC=no），該配置文件名是logind.conf.rpmnew，若是用戶使用原來的配置文件，那麼本文描述的failures將會發生。
爲了不本問題，當os升級以後，務必編輯logind.conf 文件並設置RemoveIPC=no。這在Oracle Linux 7.2 release notes中有記錄。

 

症狀：

1) Installing 11.2 and 12c GI/CRS fails, because ASM crashes towards the end of the installation.
2) Upgrading to 11.2 and 12c GI/CRS fails. 
3) After Redhat Linux is upgraded to 7.2, 11.2 and 12c ASM and database instances crash.

systemd-logind remove掉IPC objects可能在任什麼時候候發生，故障的表現能夠有很大的不一樣，下面是故障的幾個例子

Most common error that occurs is that the following is found in the asm or database alert.log:
ORA-27157: OS post/wait facility removed
ORA-27300: OS system dependent operation:semop failed with status: 43
ORA-27301: OS failure message: Identifier removed
ORA-27302: failure occurred at: sskgpwwait1

The second observed error occurs during installation and upgrade when asmca fails with the following error:
KFOD-00313: No ASM instances available. CSS group services were successfully initilized by kgxgncin
KFOD-00105: Could not open pfile 'init@.ora'

The third observed error occurred during installation and upgrade:
Creation of ASM password file failed. Following error occurred: Error in Process: /u01/app/12.1.0/grid/bin/orapwd
Enter password for SYS:
OPW-00009: Could not establish connection to Automatic Storage Management instance
2015/11/20 21:38:45 CLSRSC-184: Configuration of ASM failed
2015/11/20 21:38:46 CLSRSC-258: Failed to configure and start ASM

The fourth observed error is the following message is found in the /var/log/messages file around the time that asm or database instance crashed:
Nov 20 21:38:43 testc201 kernel: traps: oracle[24861] trap divide error
ip:3896db8 sp:7ffef1de3c40 error:0 in oracle[400000+ef57000]

變通的解決方法：
1) Set RemoveIPC=no in /etc/systemd/logind.conf

2) Reboot the server or restart systemd-logind as follows:
    # systemctl daemon-reload
    # systemctl restart systemd-logind

補丁：
從RHEL7.2遷移到Oracle Linux7.2能夠解決本問題。
如果遷移到Oracle Linux7.2不可能，請使用上述變通的解決方法

歷史：
2015年11月23日，本文章被創建。

轉自：https://blog.csdn.net/msdnchina/article/details/50864065?tdsourcetag=s_pctim_aiomsg