8 Messaging Server Pre-Installation Tasks

This chapter provides information on the pre-installation tasks you must complete before you can install Oracle Communications Messaging Server.

For information about Cassandra message store pre-installation tasks, see Messaging Server Installation and Configuration Guide for Cassandra Message Store.

Creating a UNIX System User and Group

System users run specific server processes, and privileges need to be given to these users so that they have appropriate permissions for the processes they are running.

Set up a system user account and group for Messaging Server, and set permissions for the directories and files owned by that user.

To Create a UNIX System User and Group

To create a UNIX system user and group, follow the steps below:

Log in as root.
Create a group name for server processes to which your system users belong.

For example:
```
groupadd mail
```
Create a user name for system processes and associate it with the group name you just created. In addition, set the password for that user.

For example:
```
useradd -g mail mailsrv
```
The useradd and usermod commands are located in the /usr/sbin directory. See UNIX man pages for more information.
You might also need to check the /etc/group and /etc/passwd files to be sure that the user has been added to the system group that you created.

Note:

Should you decide not to set up UNIX system users and groups prior to installing Messaging Server, you are able to specify them when you run the configuration script. However, if the user name for server processes already exists, then the primary group for that user name is used, and the configuration script does not prompt for the option.

Checking the DNS Configuration

Check that DNS is running and configured properly for the Messaging Server host. The following example is for a host running Solaris 10 OS. The configuration is slightly different for a host running Solaris 11 OS.

To Check the DNS Configuration

To check the DNS configuration, follow the steps below:

Ensure that DNS is properly configured and that it is clearly specified how to route to hosts that are not on the local subnet.
- The /etc/defaultrouter file should contain the IP address of the gateway system. This address must be on a local subnet.
- The /etc/resolv.conf file exists and contains the proper entries for reachable DNS servers and domain suffixes.
- In the /etc/nsswitch.conf file, the hosts: and ipnodes: line has the files, dns and nis keywords added. The keyword files must precede dns and nis. So if the lines look like this:
```
hosts: nis dns files
ipnodes: nis dns files
```
  They should be changed to this:
```
hosts: files nis dns
ipnodes: files nis dns
```
Make sure that the FQDN is the first host name specified after the IP address in the /etc/hosts file.

If your Internet host table in your /etc/hosts file looks like this:
```
123.456.78.910 budgie.west.example.com
123.456.78.910 budgie loghost mailhost
```
Change it so that there is only one line for the IP address of the host. Be sure the first host name is a fully qualified domain name. For example:
```
123.456.78.910 budgie.west.example.com budgie loghost mailhost
```
You can verify that the lines are read correctly by running the following commands:
```
getent hosts ip_address
getent ipnodes ip_address
```
If the lines are read correctly, you should see the IP address followed by the FQDN and then the other values. For example:
```
getent hosts 192.18.126.103
192.18.126.103 budgie.west.example.com budgie loghost mailhost
```

Checking the Number of File Descriptors

The default installation of Linux uses 1024 file descriptors, which is insufficient for the correct operation of Messaging Sever. Messaging Server needs the maximum file descriptors set to 16384. Messaging Server processes rely heavily on multi-threading and this operating system restriction on the number of processes, if not changed as described below, can have random severe results.

To Check and Change the Number of File Descriptors

In a terminal window, as root user, verify the number of file descriptors.
```
ulimit -n
1024
```
If this number is less than 16384, you need to increase the value.
To change the number of file descriptors, add the following to the /etc/sysctl.conf file. Or, if the parameter is already set, increase the value to 16384.
```
fs.file-max = 16384
```
Add the following two lines to the /etc/security/limits.conf file.
```
# Increase max file descriptors
* - nofile 16384
```
Note:
Be careful when editing configuration files to not introduce extra spaces and lines, as this could cause errors. If you do accidentally type extra spaces, try copying existing lines and then overwriting them (by pasting) to get rid of any extra spaces. Using a text editor that displays hidden characters can also help.
Reboot the system for the value to take effect.
In a new terminal window, as root verify the change.
```
ulimit -n
16384
```

Installing Directory Server

Messaging Server uses Oracle Directory Server Enterprise Edition to store and access LDAP data for individual users, groups, and domains.

If your site does not currently have Directory Server deployed, and you need to install it, see the Oracle Directory Server Enterprise Edition documentation at:

http://docs.oracle.com/cd/E29127_01/index.htm

Prior to installing and configuring Messaging Server, you must also prepare the Directory Server LDAP schema by running the comm_dssetup.pl script. This script, which is provided as part of the Messaging Server Installer, adds the necessary Communications Suite schema to the LDAP. See "Preparing Directory Server" for more information.

Note:

Always run the latest version of comm_dssetup.pl if you are upgrading any of the component products that depend on Directory Server.

Some LDAP object classes in the Communications Suite schema specifically support Messaging Server. For more information, see the discussion on understanding the schema that is used by Messaging Server in the Schema Reference.