Error Ora-01102:cannot How to handle mount Database in EXCLUSIVE mode

Problem Description:

In a RAC environment, you want to turn on the archive log, which uses

SQL> alter system setcluster_database=falsescope=spfile;-->把集群修改为单实例

Modify the master node and restore the two nodes of the cluster.

SQL> alter system  set cluster_database= true scope=spfile;-->把集群修改为双实例

The current database master node is open and the query status is open

The standby node is already in the shutdown state, starting the current node times:

Ora-01102:cannot mount Database in EXCLUSIVE mode
Through the online access to information, may be as follows, I put the relevant solutions to copy come to you can refer to

Analysis Reason:

First, in the HA system, there are already other nodes started the instance, the dual-machine shared resources (such as the disk array on the bare device, the cluster is not properly opened ) occupied;

Second, when Oracle is abnormally closed, there are resources not released , there are generally the following possibilities,

1, Oracle's shared memory segment or semaphore is not released;

2, Oracle's background process (such as Smon, Pmon, DBWN, etc.) is not closed;

3. the files lk<sid> and sgadef<sid>.dbf files used to lock the memory are not deleted.

Solution Ideas:

When a 1102 error occurs, the following process can be used to check and debug:

If it is an HA system, check if the other node has launched an instance to check if the Oracle process exists, if there is a kill process to check if the semaphore exists, if present, clear the semaphore to check if the shared memory segment exists, and if present, clear the shared memory segment check lock memory file Lk<sid > and sgadef<sid>.dbf are present, and if they exist, they are deleted.

Specific practices:

First, although our system is an HA system, the instance of the standby node is always off, which can be verified by checking the database state on the standby node.

Second, because the system has changed the state of the cluster, whether after the modification does not take effect, then is to query the current cluster state

SQL> show parameter cluster NAME                     TYPE     VALUE ------------------------------------ ----------- ------------------------------ cluster_database             boolean     fales
cluster_database_instances         integer     2 cluster_interconnects             string

It may be possible to determine what the problem is, it may be that the parameters are not in effect after the current modification, need to be re-modified to take effect, is the first case

Restart the database Mount state

SQL> alter system setcluster_database=truescope=spfile;

Modify the database to open state, and then try to prepare the node can start successfully, the results found that the boot success

After modifying the RAC environment parameters, it is best to verify that the successful master is modified

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Error Ora-01102:cannot How to handle mount Database in EXCLUSIVE mode