Advanced DBA Certification Guide and Reference for DB2 Universal Database v8 for Linux, UNIX, and Windows

The database partition configuration file contains configuration information that tells DB2 which database partition on which server participates in an instance. There is a db2nodes.cfg file for each instance in a partitioned database environment.

• On Linux and UNIX : $HOME/sqlllib/db2nodes.cfg

• On Windows : <install_path>\sqllib\db2\db2nodes.cfg

The db2nodes.cfg file must contain one entry for each database partition on a particular server that will participate in the instance. When you create an instance, the db2nodes.cfg file is automatically created, and an entry for the instance-owning database partition is added.

On Linux and UNIX, the database partition configuration file (db2nodes.cfg) uses the following format:

dbpartitionnum hostname port_number netname -------------- -------- ----------- ------- 0 host1 0 net1 1 host1 1 net1 2 host2 0 net2

where:

dbpartitionnum is the number DB2 uses to identify a database partition. Database partition numbers must be:

• Unique

• In ascending order (gaps can exist in the sequence)

• In the range between 0 and 999

hostname is the network interface DB2 uses to communicate between database partitions.

• It is defined in the /etc/ hosts file

port_number is the logical port DB2 uses to distinguish between multiple database partitions on a server. The logical port field must satisfy the following:

• Unique per entry per server

• If not specified, the default is 0

• If using multiple database partitions on a single server, the logical port number must start at 0 and continue with an increment of one, i.e., next port would be 1, 2, 3, and so on

• A range of ports must be defined in the /etc/services

• Reserves one port for each database partition

netname is the switch network interface DB2 uses to improve performance, specific on RS/6000 SP, using the switch technology (optional).

• If not specified, the default is host name

On Windows, the database partition configuration file (db2nodes.cfg) uses the following format:

dbpartitionnum hostname machinename port_number netname -------------- -------- ----------- ----------- ------- 0 host1 machine1 0 net1 1 host1 machine1 1 net1 2 host2 machine2 0 net2

where:

dbpartitionnum is the number DB2 uses to identify a database partition. Database partition number must be:

• Unique

• In ascending order (gaps can exist in the sequence)

• In the range between 0 and 999

hostname is the TCP/IP host name.

• It is defined in the c:\winnt\system32\drivers\etc\hosts

machinename is the workstation name if the database partition is created on a remote machine.

port_number is the logical port DB2 uses to distinguish between multiple database partitions on a server. The logical port field must satisfy the following:

• Unique per entry per server

• If not specified, the default is 0

• If using multiple database partition on a single server, the logical port number must start at 0 and continue with an increment of one, i.e., next port would be 1, 2, 3, and so on

• A range of ports must be defined in c:\winnt\system32\drivers\etc\services

• Reserves one port for each database partition

netname is the network name or IP address (optional).

Windows Considerations

For DB2 on Windows, the database partition configuration file is created for you when you create an instance.

• Use the db2nlist command to list all database partitions in a database partition server.

• Use the db2ncrt command to add a database partition server to an instance.

• Use the db2ndrop command to drop a database partition server to an instance.

• Use the db2nchg command to modify a database partition server configuration, including moving the database partition server from one machine to another, changing the TCP/IP host name, or selecting a different logical port or network name.

• Do not attempt to create or modify the database partition configuration file manually.