LDM Preinstallation Steps

The platform on which the LDM package is to be installed must be prepared in advance prior to unpacking and installing the LDM distribution.

Contents

• Steps to Perform as root
• Steps to Perform as the LDM User

Steps to Perform as root

Create the LDM user-account

This is, necessarily, a system-dependent operation. Consult with your system's administrator, if necessary.

Keep the following in mind when creating the account:

• The canonical name of the user is "ldm", but that's not a requirement.
• The installation process is simpler if the LDM user's home-directory is on local disk. "/home/ldm" and "/home/ldm are viable candidates.
• Use a group ID that allows other non-LDM processes to write files (decoders, etc.). The McIDAS and GEMPAK users are often members of this group.

Workshop-specific instructions.

Ensure that TCP connections can be made

If the computer on which the LDM runs has firewall (alias, packet filtering) rules, then these rules must be configured to allow connections to and from the LDM. How this is done is operating-system specific, so you might have to consult with your system or network administrator.

In order for the LDM system to send data to a downstream LDM, the firewall rules must allow incoming TCP connections to the port on which the LDM server is listening (the default is 388). An example of ensuring this for firewall rules based on iptables(8) is the command iptables -A INPUT -p tcp --dport 388 -j ACCEPT

Similarly, in order for the LDM to receive data from an upstream LDM, the firewall rules must allow outgoing TCP connections to the port on which the upstream LDM server is listening (the default is 388). Because most sites don't bother filtering outgoing connections, this configuration step is usually not necessary.

Workshop-specific instructions.

Steps to Perform as the LDM User

Edit the LDM user's profile-file

As the LDM user, add the following entries to the appropriate login profile-file of the LDM user's user-shell. The profile-file should be the one that the user-shell reads when it's a login shell (e.g., .bash_profile, .login).

SysManPath is the pathname for the manual-pages of the operating system (e.g., /usr/man or /usr/share/man). The MANPATH environment variable might already contain this path.

If necessary, modify the setting of the PATH environment variable above to ensure that the necessary build utilities can be found.

Don't forget to source the profile-file so that the modifications take effect. For example:

Workshop-specific instructions.