I believe this is so that small jobs will naturally go on older, slower nodes first - leaving the bigger,better ones for jobs that actually need them.
Merlin -- Merlin Hartley IT Support Engineer MRC Mitochondrial Biology Unit University of Cambridge Cambridge, CB2 0XY United Kingdom > On 5 Sep 2019, at 16:48, Douglas Duckworth <dod2...@med.cornell.edu> wrote: > > Hello > > We added some newer Epyc nodes, with NVMe scratch, to our cluster and so want > jobs to run on these over others. So we added "Weight=100" to the older > nodes and left the new ones blank. So indeed, ceteris paribus, srun reveals > that the faster nodes will accept jobs over older ones. > > We have the desired outcome though I am a bit confused by two statements in > the manpage <https://slurm.schedmd.com/slurm.conf.html> that seem to be > contradictory: > > "All things being equal, jobs will be allocated the nodes with the lowest > weight which satisfies their requirements." > > "...larger weights should be assigned to nodes with more processors, memory, > disk space, higher processor speed, etc." > > 100 is larger than 1 and we do see jobs preferring the new nodes which have > the default weight of 1. Yet we're also told to assign larger weights to > faster nodes? > > Thanks! > Doug > > -- > Thanks, > > Douglas Duckworth, MSc, LFCS > HPC System Administrator > Scientific Computing Unit <https://scu.med.cornell.edu/> > Weill Cornell Medicine" > E: d...@med.cornell.edu <mailto:d...@med.cornell.edu> > O: 212-746-6305 > F: 212-746-8690
