@@ -12,6 +12,7 @@ SRVOAD is a shared computation server used by members of TASK and MODELIS teams.
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@@ -12,6 +12,7 @@ SRVOAD is a shared computation server used by members of TASK and MODELIS teams.
## Common errors
## Common errors
1. With htop you will see 80 threads available. The server is composed of 40 physical cpus (core) with hyperthreading (not 80). A single physical CPU will never be used to run two different tasks. The `cpus-per-task` option defines the number of **threads** you want to use. If you ask for an odd number of threads, slurm will always allocate the even number above (ie. `cpus-per-task=1` slurm will allocate 2 threads per task).
1. With htop you will see 80 threads available. The server is composed of 40 physical cpus (core) with hyperthreading (not 80). A single physical CPU will never be used to run two different tasks. The `cpus-per-task` option defines the number of **threads** you want to use. If you ask for an odd number of threads, slurm will always allocate the even number above (ie. `cpus-per-task=1` slurm will allocate 2 threads per task).
2. If you use an SBATCH script to run your code, don't use srun in it. In fact, using srun commands in a SBATCH script is equivalent to using "srun srun my_app" and often lead to problems (e.g. different settings).
2. If you use an SBATCH script to run your code, don't use srun in it. In fact, using srun commands in a SBATCH script is equivalent to using "srun srun my_app" and often lead to problems (e.g. different settings).
3. Every interactive process has a limit of 2GB of RAM, **even with `salloc` or `srun`**.
## Know your machine
## Know your machine
A [DELL R440](https://www.dell.com/fr-fr/shop/productdetailstxn/poweredge-r440) 1U server
A [DELL R440](https://www.dell.com/fr-fr/shop/productdetailstxn/poweredge-r440) 1U server
