>On Sun, 14 Aug 2005, Ken Fuchs wrote: >> I still think a cluster is what you need. There are several Linux >> cluster distributions that are available on Live CDs that are easy to >> setup. They should also have hard drive install options. >> How well a cluster will work depends on how fast the interconnect is and >> how much information must flow between nodes? These same issues will be >> need to be addressed in a single system with several multi-core CPUs, >> although the interconnect is bound to be much faster in a single >> (non-cluster) system. Mike Miller wrote: >Why do I need a cluster? I don't fully understand how clusters can work >for me, but I am very interested. In fact, I have been thinking that I >would expand the system in the future to include other machines in a >cluster configuration, but right now I think one might be enough. I meant to say that I believe a cluster could meet your needs. The fact that you are considering adding machines in the future to form a small cluster suggests that you might find it worthwhile to temporarily convert a computer lab of networked x86 machines (any OS) into a Linux cluster as an experiment to see how well it may suit your application. Here are just a handful of Linux Cluster Live CD distributions: http://clusterix.livecd.net/ http://bofh.be/clusterknoppix/ http://pareto.uab.es/mcreel/ParallelKnoppix/ The last one may be the easiest to setup. >If I have a single machine with multiple sockets/cores, the OS will >transparently handle the multiple jobs and level the load across the >cores. So the single-machine-multiple-core setup is easy to work with. >I'm not as confident about the cluster setup. Clearly, if you have enough money to buy a single system to meet your needs and your application doesn't translate to a cluster efficiently, a cluster is not the right solution. >In case someone on this list has some experience or knowledge in this >area, here are some questions: > >(1) How are jobs handled in a Linux cluster? Obviously, someone logs into >one machine and jobs are sent to that machine or to other machines, but >how does the system decide where to send a job? To submit a job, does the >user have to specify any parameters to determine where/how it will run? > >(2) If different nodes in the cluster have different amounts of RAM >available, how does the system decide where the more memory-intensive jobs >will run? If it does this automatically, ignoring memory requirements, is >it possible to request that a certain job go to a certain node? > >In general, I need to understand job control in the cluster system to >understand how that system can be used for the kind of work I do. You might consider just devoting a handful of networked machines (preferably via 1Gbit Ethernet or faster) and run a Live CD cluster on it to see how it works first hand. Sincerely, Ken Fuchs <kfuchs at winternet.com>