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The salloc command allocates resources within a queue and opens a shell from which commands using these resources can be launched with the srun command. This is mainly used for testing. Exiting the shell will cancel the resource allocation. If you want to keep the resource allocation (and job running) and logout from your terminal, you will need to run salloc within a screen command (then don't forget to cancel the resource allocation later!).
ebuchlin@cluster-head:~$ salloc -p flarecast -n 2 # 2 jobs in partition "flarecast"
salloc: Granted job allocation 2765
ebuchlin@cluster-head:~$ srun hostname
cluster-r730-1
cluster-r730-1
ebuchlin@cluster-head:~$ exit
salloc: Relinquishing job allocation 2765
salloc: Job allocation 2765 has been revoked.
ebuchlin@cluster-head:~$
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