technical:slurm:node-memory-sizes

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technical:slurm:node-memory-sizes [2019-02-18 12:25] – [Nominal node memory size is not an appropriate limit] freytechnical:slurm:node-memory-sizes [2019-02-18 12:32] – [Requesting specific node types] frey
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 A workgroup QOS which under v1.1.3 had ''cpu=756,mem=3801088'' reflecting (13) //Gen1/128 GiB// nodes and (8) //Gen1/256 GiB// nodes will change to ''cpu=756,mem=3698688'' to reflect the RealMemory sizes specified above. A workgroup QOS which under v1.1.3 had ''cpu=756,mem=3801088'' reflecting (13) //Gen1/128 GiB// nodes and (8) //Gen1/256 GiB// nodes will change to ''cpu=756,mem=3698688'' to reflect the RealMemory sizes specified above.
 +
 +==== Requesting specific node types ====
 +
 +Our Slurm has always defined several //features// on each node in the cluster:
 +
 +<code bash>
 +$ scontrol show node r00n00 
 +NodeName=r00n00 Arch=x86_64 CoresPerSocket=36
 +   CPUAlloc=0 CPUErr=0 CPUTot=72 CPULoad=0.07
 +   AvailableFeatures=E5-2695,E5-2695v4,128GB,HT
 +   ActiveFeatures=E5-2695,E5-2695v4,128GB,HT
 +      :
 +</code>
 +
 +It is possible to constrain a job to execute on a node with a specific nominal memory size using these features:
 +
 +<code bash>
 +$ sbatch … --constraint=128GB …
 +$ sbatch … --constraint=256GB …
 +$ sbatch … --constraint=512GB …
 +</code>
 +
 +The other features reflect the model processor present in the node.  All Gen1 nodes use the Intel ''E5-2695v4''; node ''r00n00'' is part of the ''devel'' partition and has hyperthreading enabled, hence the ''HT'' feature.
 ===== Implementation ===== ===== Implementation =====