Starting up an OPS database is quite different from starting up a standalone database.
You can start an Oracle Parallel Server instance in either exclusive mode or shared mode. In exclusive mode, only one instance can mount and open the database. In shared mode, multiple instances can mount and open the database simultaneously. The initialization parameter PARALLEL_SERVER determines which mode is used when a database is started. Shared mode is the normal operating mode for an OPS database. Exclusive mode is required for certain administrative tasks such as switching ARCHIVELOG mode on or off. (See Section 7.4.1 later in this chapter.)
If you are using Oracle8 (not Oracle8i ), you must start Group Membership Services (GMS) before you can start an OPS instance. This is true regardless of whether you are starting the instance in shared or exclusive mode. The next few sections show you how to start up an OPS database in exclusive mode and shared mode and how to start GMS.
To start up an instance in exclusive mode, you must choose an instance to use, and you must set the initialization parameter PARALLEL_SERVER to FALSE for that instance. Only one instance can open a database in exclusive mode. In order for that to happen, you must first shut down all the instances that normally open the database in shared mode.
While exclusive mode implies that only one instance has the database open, the reverse is not necessarily true. Suppose that you have a two-instance OPS database, with both instances running in shared mode. If you shut down instance 2, instance 1 is not automatically converted to exclusive mode. One instance in shared mode is not equivalent to one instance in exclusive mode.
Once you have PARALLEL_SERVER set to FALSE for the instance you want to start, you can use the STARTUP command from Server Manager to start the instance.
Tip
The SHARED, PARALLEL, and EXCLUSIVE options of the STARTUP command are obsolete in Oracle8. You can issue the STARTUP EXCLUSIVE and STARTUP PARALLEL commands from Server Manager, but the result still will be controlled by the PARALLEL_SERVER initialization parameter. The EXCLUSIVE, SHARED, and PARALLEL options of the STARTUP command are ignored.
To start up an instance in shared mode, set the initialization parameter PARALLEL_SERVER to TRUE. You can start multiple instances in shared mode at the same time. For an instance to start in shared mode, it must have the following:
At least one rollback segment
At least one thread of redo log having at least two redo log groups
Creating rollback segments and redo log threads is discussed earlier in this chapter. You can use the STARTUP command from Server Manager to start each instance separately, or you can use either the opsctl utility or Oracle Enterprise Manager (OEM) to start all the instances at once.
For Oracle8 (not Oracle 8i ), the Group Membership Services (GMS) (described in Chapter 6) must be running on each node in which you want to start an OPS instance. Several OPS platforms provide a utility named ogmsctl that you can use to start and stop GMS. Refer to the Oracle installation manual for your platform to find out if your platform supports ogmsctl.
The ogmsctl utility is installed on your server when you install Oracle with the OPS option. You can use ogmsctl to start, stop, and check the status of GMS. To start GMS on a node, issue the following command at the operating system prompt:
ogmsctl start
To stop GMS on a node, issue the following command at the operating system prompt:
ogmsctl stop
To check the status if GMS is running on a node, issue the following command at the operating system prompt:
ogmsctl status
Several OPS platforms provide the opsctl utility, which can be used to start and stop an OPS instance. The opsctl utility is installed on your server when you install Oracle with the OPS option. To find out if your platform supports opsctl and for information on configuring opsctl, refer to your platform-specific Oracle installation manual.
The opsctl utility can start and stop three stages of an OPS instance: GMS, the instances, and the listener. These stages may be started and stopped individually or all together. You can use opsctl on one node to start or stop any of these three stages on all nodes of an OPS database.
To start GMS, the instances, and the listeners on all nodes, issue the following command at the operating system prompt:
opsctl start -s gms,inst,lsnr
If you are running a two-node OPS configuration, your output will look like this:
GMS successfully started on node# 1 ( 'n01' ) GMS successfully started on node# 2 ( 'n02' ) Instance successfully started on node# 1 ( 'n01' ) Instance successfully started on node# 2 ( 'n02' ) Listener successfully started on node# 1 ( 'n01' ) Listener successfully started on node# 2 ( 'n02' )
In the opsctl command shown here, “gms” stands for the GMS stage, “inst” stands for the instance stage, and “lsnr” stands for the listener stage. You need to use these keywords to start the respective stages. For example, to start GMS only, but on all nodes, you can issue the following command:
opsctl start -s gms
The output from this command will resemble this:
GMS successfully started on node# 1 ( 'n01' ) GMS successfully started on node# 2 ( 'n02' )
Starting an Oracle8i OPS database is a bit different from starting an Oracle8 OPS database; this is because GMS no longer exists in Oracle8i. Follow these steps to start an Oracle8i OPS database:
Start the cluster manager software on each node on which you want to run an OPS instance. The cluster manager software is platform-specific software supplied by the hardware vendor. For more details on cluster manager, refer to Oracle Corporation’s Oracle8i Parallel Server Concepts and Administration manual and to your operating system-specific Oracle documentation.
Set the initialization parameter PARALLEL_SERVER to TRUE or FALSE, depending on whether you want to start in exclusive or shared mode.
Use Server Manager on each node to start each instance individually, or use the opsctl utility to start all instances at once.
To stop an OPS database, you can use Server Manager on each node to stop each instance individually, or you can use the opsctl utility to stop all the instances at once. To stop GMS, all instances, and all the listeners, issue the following command at the operating system prompt:
opsctl stop -s gms,inst,lsnr
Here’s what the output will look like in a two-node configuration:
Listener successfully shutdown on node# 1 ( 'n01' ) Listener successfully shutdown on node# 2 ( 'n02' ) Instance successfully shutdown on node# 1 ( 'n01' ) Instance successfully shutdown on node# 2 ( 'n02' ) GMS successfully shutdown on node# 1 ( 'n01' ) GMS successfully shutdown on node# 2 ( 'n02' )
There is no GMS in Oracle8i. To stop an Oracle8i OPS database, you can use Server Manager on each node to stop each instance individually, or you can use the opsctl command as shown here, but without the “gms” keyword, to stop all instances at once.