Anderson :
Hello Gabriel,
After following these steps I could not run any application that is distributed by the cluster. How do the processes to be distributed in the cluster automatically or as a program can take advantage of this type of cluster?

You need a message-passing interface and software which is designed for parallel processing. I suggest looking into http://www.open-mpi.org/

Anderson :

Hello Gabriel,
After following these steps I could not run any application that is distributed by the cluster. How do the processes to be distributed in the cluster automatically or as a program can take advantage of this type of cluster?

You need a message-passing interface and software which is designed for parallel processing. I suggest looking into http://www.open-mpi.org/

first of all: Nice work putting all this together.

I just want to remind though that, especially, when you are looking at clusters and a few more diskless nodes, you will run into trouble.

At least I did. I have obviously one central image mounted per nfs on 44 nodes. They again get the rest (/home, /data, /srv …) over automount amp; nfs from same head node.

This leads to daily 1-2 nodes losing the autofs mounts. There seems to be problems in this scale somehow. Can’t say where the limits lie.

Cheers.

gary :

hie great article. it actually works may you please tell me the kind of physical setup you had when u did this. do you have 2 network cards and is this possible with like 1 nic and a switch

I had two NICs and a switch. Because it’s its own private network, using a secondary NIC was easiest. You could just as easily use a virtual network adapter and a single NIC, however.

Sune Beck :

With this setup it seems the head server would become single-point-of-failure. Is there some way to load the node OS onto a local disk (or perhaps in-memory) upon boot and then continue from there?

It would be nice to, say, replace a switch or the head machine without affecting the (possibly high number of) nodes.

What is the best solution for this?

That’s an excellent point. The point of this particular setup was to setup a very fast, cheap, diskless cluster. You could very easily implement this in such a way that the disk storage was on a SAN or NAS instead, which would provide a more robust way to implement storage. I am intrigued by the idea of loading the root image into a ramdisk, but it would require an extra couple GB of RAM to do this, which is impractical for the configuration I’ve got. Let me know if you experiment with that particular idea any further.

It would be nice to, say, replace a switch or the head machine without affecting the (possibly high number of) nodes.

What is the best solution for this?