# Interactive Sessions

Slurm allow interactive sessions into the workernodes, using ssh, but within a valid job allocation, normal ssh are disabled. The interactive session can be created on the scope of normal partitions but those jobs will have the same priority as a regular job.

There is a limitation of 1 job and 1 task per node on partitions ***hpc*** and ***gpu***, we would like to encourage users to close sessions as soon as possible to give all a good chance to use the resources.

> The *FCT* grant users should use the partition *fct* instead in the examples bellow.

## Starting srun Session

The most simple way to start an interactive session is:

	[user@cirrus01 ~]$ srun -p hpc --job-name "my_interactive" --pty bash -i
	srun: job 72791 queued and waiting for resources
	srun: job 72791 has been allocated resources
	[user@hpc059 ~]$

You will have an ssh session on a worker node were other users are running jobs or interactive sessions as well, try not bother them with unsolicitated interactions, and exit the session when you are finished.

>The *FCT* call users should target the *partition* **fct** and the *QOS* associate to the user, e.g. ***"srun -p fct -q cpcaXXXX2020 ..."***, where *XXXX* is the call ID.

The ***srun*** command have the same restrictions as a normal *job* and will be aborted or refused to run when the system limits are axceeded. If you run the ***squeue*** you will see your interactive job listed as any other job:

	[user@hpc059 ~]$ squeue 
    JOBID PARTITION     NAME     USER ST       TIME  NODES NODELIST(REASON) 
    72818       hpc my_inter     user  R       2:03      1 hpc059 

## Starting salloc Session

The ***salloc*** is setup to behave like the ***srun*** command, for example:

	[user@cirrus01 ~]$ salloc -p hpc --job-name "my_interactive" 
	salloc: Pending job allocation 72818
	salloc: job 72818 queued and waiting for resources
	salloc: job 72818 has been allocated resources
	salloc: Granted job allocation 72818
	salloc: Waiting for resource configuration
	salloc: Nodes hpc059 are ready for job
	[user@hpc059 ~]$

>Once again the *FCT* call users should target the *partition* **fct** and the *QOS* associate to the user