DB2 Data Links Manager Quick Beginnings

Additional Installation Considerations in JFS Environments

If you plan to deploy DB2 Data Links Manager in a Journaled File System (JFS) environment, you should also take the following information into consideration:

Operating system level

Ensure that you are running AIX Version 4.2.1 or later. To check the level of the operating system, enter the oslevel command.

Version levels of DB2 Data Links and DB2 Universal Database

DB2 Universal Database and DB2 Data Links Manager can be any combination of Version 6.1 and Version 7.1. For example, DB2 UDB can be at Version 6.1 and Data Links Manager can be at Version 7.1. To check the version of DB2 that resides on a workstation, enter the db2level command.

DLMADMIN username

During installation, you will be given the option to create the DB2 Data Links Manager Administrator (DLMADMIN) user. These installation instructions assume that you select this option.

When you select to create the DLMADMIN username, the db2setup utility will create this user with the username dlfm and password ibmdb2. You can accept these default values, specify an existing username, or create a different username by changing the default values. For security reasons, we recommend that you specify your own username and password because the default values are used in every DB2 Data Links installation and therefore are well known. The DLMADMIN username will also be the name of the Data Links Manager instance.

If you want to specify your own existing username, the account you specify:

• Must not have its home directory reside on a file system that is using a Data Links Filesystem Filter.
• Must have a username that is eight characters or less.
• Must not be a user with root authority.

To create a username for use as the DB2 Data Links Manager Administrator (DLMADMIN):

1. Log in as a user with root authority.
2. Create the a group for the DB2 Data Links Administrator (for example, dlfmgrp) and username (for example, dlfm), using the /home/dlfm directory as the home directory of the DLMADMIN, by entering the following commands:

      mkgroup dlfmgrp
      mkuser pgrp='dlfmgrp' groups='dlfmgrp' home='/home/dlfm' dlfm
   

3. Assign a password to this username by entering the passwd username command, where username is the username that you created.

The DB2 Data Links Manager Administrator (DLMADMIN) should never own files or directories on a file system that is under the control of a Data Links Filesystem Filter. The DLMADMIN should only be used to administer the Data Links File Manager.

If you create a different username by changing the default values, you must ensure that the username you specify is eight characters or less.

Disk space requirements for DLMADMIN user

Ensure that there is at least 70 MB of free disk space in the home directory where the DB2 Data Links Manager Administrator's home directory will reside. To check available free disk space, enter the df -k INSTHOME command, where INSTHOME is the home directory of the DLMADMIN user.

Determine fully qualified hostnames

You must resolve the fully qualified hostnames of your DB2 Data Links and DB2 UDB servers. You will need to know these hostnames to verify the installation.

When connecting to the DB2 Data Links File Manager, the DB2 UDB server sends the following information to the DLFM:

• Database name.
• Instance name.
• Hostname.

The DLFM then verifies this information to decide if a connection from this particular DB2 server should be allowed. The subroutine that obtains hostname information on the DB2 server, gethostbyname, looks for /etc/resolv.conf. If this file exists, the subroutine queries the domain name server. If the request to the DNS times out, the gethostbyname routine checks the local /etc/hosts file. To connect successfully to the DLFM, the name registered on the DLFM must be the one which is obtained by the gethostbyname routine on the DB2 UDB server.

To resolve the hostnames of your DB2 Data Links and DB2 UDB servers, enter the hostname command on each system. For example, this command might return dlmserver on your Data Links server.

Now enter the host dlmserver command, where dlmserver is your hostname. This command should return output similar to the following:

   dlmserver.services.com is 9.11.302.341,  Aliases:  dlmserver 

dlmserver.services.com is your fully qualified hostname name.

Repeat these steps on each DB2 Data Links and DB2 UDB server.