RemoveIPC=yes 的RHEL7.2 会crash掉Oracle asm 实例和Oracle database实例
一个在centos7.2上的11204库的实例crash了，检查alert发现如下：
Wed Sep 21 00:00:11 2016 Errors in file /apps/oracle/diag/rdbms/xberp/xberp/trace/xberp_ckpt_17537.trc: 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 Wed Sep 21 00:00:11 2016 Errors in file /apps/oracle/diag/rdbms/xberp/xberp/trace/xberp_dbrm_17523.trc: 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 Wed Sep 21 00:00:11 2016 Errors in file /apps/oracle/diag/rdbms/xberp/xberp/trace/xberp_mman_17527.trc: 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 Wed Sep 21 00:00:11 2016 Errors in file /apps/oracle/diag/rdbms/xberp/xberp/trace/xberp_j002_14570.trc: 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 CKPT (ospid: 17537): terminating the instance due to error 27157 Wed Sep 21 00:00:11 2016 Errors in file /apps/oracle/diag/rdbms/xberp/xberp/trace/xberp_j000_14566.trc: 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 Instance terminated by CKPT, pid = 17537 Errors in file /apps/oracle/diag/rdbms/xberp/xberp/trace/xberp_ckpt_17537.trc: ORA-27300: OS system dependent operation:semctl failed with status: 22 ORA-27301: OS failure message: Invalid argument ORA-27302: failure occurred at: sskgpwrm1 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 Wed Sep 21 10:20:34 2016
描述：
在centos7.2中，systemd-logind 服务引入了一个新特性，该新特性是：当一个user 完全退出os之后，remove掉所有的IPC objects。
该特性由/etc/systemd/logind.conf参数文件中RemoveIPC选项来控制。
在centos7.2中，RemoveIPC的默认值为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 and semaphores
由于Oracle ASM 和database 使用 shared memory segments ，remove shared memory segments将会crash掉Oracle ASM and database instances.
Oracle Linux 7.2 通过在/etc/systemd/logind.conf配置文件中明确设置RemoveIPC为no，Oracle Linux7.2 避免了该问题，
变通的解决方法：
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
这些错误跟os有关，在mos上有文档可能参考：
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) (文档 ID 2081410.1)