操作系统：CentOS Linux release 7.2.1511 (Core)

内存：8G

数据库版本：单实例Oracle 19.3

故障描述：

数据库启动完毕后，无业务自动关闭，检查日志发现大量ORA报错如下：

ORA-27157: 已删除了操作系统发送/等待功能

ORA-27300: 操作系统系统相关操作: semop 失败, 状态为: 43

ORA-27301: 操作系统故障消息: Identifier removed

ORA-27302: 错误发生在: sskgpwwait1

Errors in file /oracle/app/oracle/diag/rdbms/db19c/db19c/trace/db19c_lgwr_4308.trc  (incident=12161):

ORA-27157 [] [] [] [] [] [] [] [] [] [] [] []

Errors in file /oracle/app/oracle/diag/rdbms/db19c/db19c/trace/db19c_ckpt_4310.trc  (incident=12169):

ORA-27157 [] [] [] [] [] [] [] [] [] [] [] []

Errors in file /oracle/app/oracle/diag/rdbms/db19c/db19c/trace/db19c_psp0_4276.trc  (incident=12033):

ORA-27157 [] [] [] [] [] [] [] [] [] [] [] []

Errors in file /oracle/app/oracle/diag/rdbms/db19c/db19c/trace/db19c_dbrm_4296.trc  (incident=12113):

ORA-27157 [] [] [] [] [] [] [] [] [] [] [] []

Errors in file /oracle/app/oracle/diag/rdbms/db19c/db19c/trace/db19c_dbw0_4306.trc  (incident=12153):

ORA-27157 [] [] [] [] [] [] [] [] [] [] [] []

Errors in file /oracle/app/oracle/diag/rdbms/db19c/db19c/trace/db19c_mman_4286.trc  (incident=12065):

ORA-27157 [] [] [] [] [] [] [] [] [] [] [] []

USER (ospid: ): terminating the instance due to ORA error

2021-02-15T18:16:49.107290+08:00

ORA-1092 : opitsk aborting process

错误原因描述：

在rhel7.2中，systemd-logind服务引入了一个新特性：在一个user完全退出OS后会remove掉所有的IPC对象。 
该特性由/etc/systemd/logind.conf参数文件中RemoveIPC选项来控制。详细请看man logind.conf(5)。

在rhel7.2中，RemoveIPC的默认值是yes

因此，当最后一个oracle或者grid用户退出时，操作系统会remove掉这个user的shared memory segments和semaphores
而Oracle ASM和database的SGA需要使用 shared memory segments，因此remove shared memory segments将会crash掉Oracle ASM和database instances。

请参考

这个问题会影响使用shared memory segments和semaphores的所有应用，因此，Oracle ASM 实例和Oracle Database 实例均受到影响。

解决方案：