This page contains answers to some of the most frequently asked questions about the LDM.
The LDM is a distributed system for event-driven data distribution. It consists of a suite of software to select, capture, process, and distribute data products using a set of network client/server programs and their shared protocols.
The LDM software is being used by hundreds of universities and cooperating agencies and is freely available to anyone who wishes to use it. The software is copyrighted by the University Corporation for Atmospheric Research.
The LDM software is freely available for download from the Unidata Program Center.
In IRIX, version 6.1, there is a file, /etc/config/portmap.options. The -a option in this file disallows any
host trying to do an RPC call to the machine. You must explicitly allow any hosts that will connect to you. See
the man page for
portmap for more information.
On IRIX systems, a disk defragger process runs every Sunday at 4:30 a.m. out of the root account. Because the product queue is a memory-mapped I/O file, it cannot be de-fragmented on disk while it is mapped. If it is, it corrupts the queue.
The solution is to either remove the root cron job that runs
/usr/etc/fsr, or to add a -m switch
pointing to a file that does not include the file system that contains the queue. This will allow other file
systems to be de-fragmented, ignoring the data file system. See the man page for
fsr for more
4/30/96: SGI now has a patch available that seems to fix the
fsr problem: patchSG0000870 -
EFS filesystem roll-up patch for non-XFS systems.
If the LDM server does not exit cleanly, port 388 may remain registered with the portmapper, even if the server
is no longer running. Use
rpcinfo to check this:
% rpcinfo -p
If port 388 is still registered, as root, use rpcinfo to deregister the port:
% rpcinfo -d 300029 version
where version is the version number of the program that is running, which will be 5 and/or 6.