文档解释
ORA-16651: requirements not met for enabling fast-start failover
Cause: The attempt to enable fast-start failover could not be completed because one or more requirements were not met:
– The Data Guard configuration must be in either MaxAvailability or MaxPerformance protection mode.
– The LogXptMode property for both the primary database and the fast-start failover target standby database must be set to SYNC if the configuration protection mode is set to MaxAvailability mode.
– The LogXptMode property for both the primary database and the fast-start failover target standby database must be set to ASYNC if the configuration protection mode is set to MaxPerformance mode.
– The primary database and the fast-start failover target standby database must both have flashback enabled.
– No valid target standby database was specified in the primary database FastStartFailoverTarget property prior to the attempt to enable fast-start failover, and more than one standby database exists in the Data Guard configuration.
Action: Retry the command after correcting the issue:
– Set the Data Guard configuration to either MaxAvailability or MaxPerformance protection mode.
– Ensure that the LogXptMode property for both the primary database and the fast-start failover target standby database are set to SYNC if the configuration protection mode is set to MaxAvailability.
– Ensure that the LogXptMode property for both the primary database and the fast-start failover target standby database are set to ASYNC if the configuration protection mode is set to MaxPerformance.
– Ensure that both the primary database and the fast-start failover target standby database have flashback enabled.
– Set the primary database FastStartFailoverTarget property to the DB_UNIQUE_NAME value of the desired target standby database and the desired target standby database FastStartFailoverTarget property to the DB_UNIQUE_NAME value of the primary database.
这个错误表明没有满足快速启动故障转移所需的要求。
官方解释
ORA-16651 是 Oracle 数据库在尝试启用快速启动故障转移（FSFO）时可能会返回的一个错误，该错误指出发生在故障转移体系结构中的部分要求未满足，因此快速启动故障转移可能无法工作。
常见案例
ORA-16651 可能是由于没有满足安装FSFO所需的一系列要求导致的，这些要求包括：
-两个用于FSFO的数据库实例必须位于同一网络中
-两个FSFO实例必须处于“正常”状态，也就是说，它们在上次启动后没有任何错误
-两个用于FSFO的实例之间必须有有效连接
-两个用于FSFO的实例之间必须有有效的共享网络
-身份验证机制（例如密码文件）必须完全一致
一般处理方法及步骤
1.确定哪些要求没有得到满足，并根据情况进行解决；
2.确保两个FSFO实例配置完全相同；
3.确保连接和共享网络的有效性；
4.不要在实例间启用不必要的安全策略；
5.使用完善的完整备份步骤，确保能够从原始备份中恢复所有数据；
6.定期测试FSFO以确保它们处于有效状态；
7.及时解决任何遇到的问题，以防止类似ORA-16651问题的发生。
