From Debian Clusters

This is the second page of a five part tutorial on cloning worker nodes with Udpcast. The full tutorial includes

• Cloning Worker Nodes
• Udpcast Cloning: Preparing the Udp-sender
• Udpcast Cloning: Preparing the DHCP Server for PXE Booting
• Udpcast Cloning: Troubleshooting PXE Booting
• Udpcast Cloning: Imaging using Udpcast

The Udpcast Paradigm

We'll use udpcast to send out the image of one node onto all the other nodes. Udpcast is a way of sending out data to multiple locations on a network at the same time. The worker node already set up will send out its image. I'll call it the udp-sender or just sender. All the other nodes, the receiving an image and being turned into clones, will be udp-receivers or receivers. The udp-receivers require a slightly more complicated setup than the sender, because the receivers can't boot off their hard drives if they haven't had an operating system installed. Instead, they'll boot off the network before running udp-receive.

Updating the Udp-sender's Image

The udp-sender is the machine that will be cloned. It's the worker node currently set up that all the other worker nodes will be imaged from. Because each of the udp-receivers will be cloned into exactly copies of the sender, it's important to make sure the sender's hard drive is in exactly the state you want it to be in prior to cloning!

Installing Udpcast

The quickest way to install udpcast on Debian is to apt-get install udpcast. However, the version of udpcast obtained with apt-get is significantly older than the current version. The worker nodes will use a bootable image with a current version of udpcast, and installing the older version on the udp-sender causes problems. In other words, udpcast needs to be installed from source. The source can be found on the Udpcast site.

You'll want to keep your all your source files in one area. I'd recommend keeping them on an NFS mount, particularly since all the nodes don't need a copy of this. From /shared/source/ on my machine, I executed

wget http://udpcast.linux.lu/download/udpcast-20070602.tar.gz

Next the tarball needs to be untarred:

tar xvzf udpcast*.tar.gz

It's a pretty standard ./configure, make, make install process. From within the directory, execute

./configure -prefix=<install location>

If you don't have a C compiler, you'll need to get that before ./configure can complete successfully. After it does, run

make

and then

make install

Type which udp-sender afterward to make sure that the binary was installed someplace within your path. (If it wasn't, do an updatedb and then udp-sender, and add the location to your Bash PATH.)