Managing Instances

The default instance for a particular system is defined by the DB2INSTANCE environment variable, and this is the instance used for most operations. However, as mentioned earlier, there are times when it is advantageous to create multiple instances on the same physical workstation (server). Reasons for creating multiple instances include:

• To separate your production environment from your development environment

• To obtain optimum performance for special applications (for example, you may choose to create multiple instances for several applications and fine-tune each instance specifically for the application(s) it will service)

As you might imagine, DB2 provides several commands that are used to create and manage instances. These commands, which are referred to as system commands because they are executed from the system command prompt rather than from the DB2 Command Line Processor (CLP), are listed in Table 4-1.

Table 4-1: DB2 9 Instance Management Commands
Open table as spreadsheet

Command …	Purpose …
db2icrt [InstanceName]	Creates a new instance
db2idrop [InstanceName]	Deletes (drops) an existing instance
db2ilist	Lists all instances that have been defined
db2imigr [InstanceName]	Migrates an existing instance to a newer version of DB2 9
db2iupdt [InstanceName]	Updates an existing instance to take advantage of new functionality that is provided when product fix packs are installed (also used to convert a 32-bit instance to a 64-bit instance)
db2start	Starts the DB2 Database Manager background processes for the current instance
db2stop	Stops the DB2 Database Manager background processes for the current instance

Tip 

Although basic syntax is presented for the instance management commands shown in Table 4-1, the actual syntax supported may be more complex. To view the complete syntax for or to obtain more information about a specific DB2 command, refer to the IBM DB2 9 Command Reference.