Jie, I bet that more than a few people on this list have done exactly what you are describing below. All of the DRM software suites I mentioned in the last email will handle the task of batching, scheduling and executing your blast and other jobs. If you are looking for the free ones you have the following options: o OpenPBS: http://www.openpbs.org o GridEngine: http://www.sun.com/gridware/ o Condor: http://www.cs.wisc.edu/condor/ OpenPBS is probably the most popular right now especially as it is often dropped in by default when you by a generic linux cluster or compute farm from somebody. Veridian systems (the people who make and market the commercial variant) provide support for OpenPBS via a fairly active mailing list. I only recommend OpenPBS to people and groups who are comfortable getting down and dirty with the source code and scheduler minutae. It is not an appropriate choice for clusters where for instance it is expected that corporate IT types will be responsible for administration tasks. Platform used to spread FUD about OpenPBS by claiming that OpenPBS cannot handle more than 5,000 jobs without losing/dropping some of them into a "black hole". There is apparently some grain of truth to his if you read some of the comments in the beowulf mailing lists. One thing that I don't like about OpenPBS is that often times the answer that people give on the support mailing list is "upgrade to PBSPro to get rid of that problem". There seem to be enough unfixed bugs and stability issues with the OpenPBS product that I usually tell people that if they are interested in PBS they would be better off in the long run by purchasing the commercial version. Veridian sells the commercial version (with source) for a very reasonable price (last time I checked it was roughly $100 USD per CPU). I can't comment on Condor all that much except to say that I know there are at least a few academic institutions who swear by it and easily cope with tens of thousands of jobs. I've never run into condor outside of academia though. GridEngine works great and is getting better all the time. It's also free and has no trouble scaling up to hundreds of nodes and many thousands of jobs. The company I work for pretty much exclusively uses Platform LSF or GridEngine for the informatics systems we work on. The software layer is an important part but it is not 100% of the solution. Make sure that you purchase your cluster from someone who knows how you are going to use it (and how Blast behaves). At the end of the day a well-designed cluster architecture is going to be more important than your eventual choice of load management layers. -Chris jie hu wrote: > Chris, > > Thank you very much for your info. We are considering to buy this Linux > cluster with 30-40 processors. It will run other applications in > addition to BLAST. For BLAST part, it will be used for batch job. For > example, we want our tens of thousands of sequences to be blasted every > week. So basically, I am trying to get some program that will allow me > to run this batch BLAST on the Linux cluster. I heard there are such > programs freely available and I only need to write some shell scripts or > perl to get it running. > > Jie