1、 Oracle无法动态注册
在SQL*PLUS下多次输入alter system register.监听器的状态始终显示为The listener supports no services。
可查看listener.ora里面的IP或主机名是否与/etc/hosts里面的相对应。
2、 ORA-00845: MEMORY_TARGET not supported on this system
Oracle解释如下：
[oracle@node3 ~]$ oerr ora
, , "MEMORY_TARGET not supported on this system"
// *Cause: The MEMORY_TARGET parameter was not supported on this operating system or /dev/shm was not sized correctly on Linux.
// *Action: Refer to documentation for a list of supported operating systems. Or, size /dev/shm to be at least the SGA_MAX_SIZE on each Oracle instance running on the system.
其实，在启动过程中，告警日志会报以下错误：
WARNING: You are trying to use the MEMORY_TARGET feature. This feature requires the /dev/shm file system to be mounted for at least bytes. /dev/shm is either not mounted or is mounted with available space less than this size. Please fix this so that MEMORY_TARGET can work as expected. Current available is and used is bytes. Ensure that the mount point is /dev/shm for this directory.
memory_target needs larger /dev/shm
原因：AMM是11g引入的新特性，它会利用到Linux系统中的/dev/shm，/dev/shm必须大于或等于memory_target。
解决方法：
1> 立即生效--注意：/dev/shm的size值必须为整数,默认是内存的一半
[root@node3 oracle]# umount tmpfs
[root@node3 oracle]# mount -t tmpfs shmfs -o size=400m /dev/shm
2> 修改/etc/fstab
tmpfs /dev/shm tmpfs defaults,size=400m
也可以先修改/etc/fstab,然后用 mount -o remount /dev/shm重新挂载/dev/shm
在RHEL6以上是系统的一个bug，即便在/etc/fstab中修改了/dev/shm的值，重启后依然恢复到内存的一半。
https://bugzilla.redhat.com/show_bug.cgi?id=669700，关于网上说的修改/etc/rc.d/rc.sysinit文件，经测试，仍然无法解决问题，反而会导致其它的盘没有挂载。
最后，只能将 mount -o remount /dev/shm编辑到/etc/rc.local文件中
3. ORA-29701: unable to connect to Cluster Synchronization Service
手动启动CSS：crsctl start res ora.cssd
4. ORA-12641: Authentication service failed to initialize
看一下$ORACLE_HOME/network/admin/sqlnet.ora文件中SQLNET.AUTHENTICATION_SERVICES的参数是否为all了。