====== Individual logs for task array and srun jobs ======

There are a myriad of ways of capturing output from running Slurm tasks. Normally all output, regardless of number of parallel tasks is captured by the main Slurm output file.

Below are three additional options to alter your Slurm job script, to capture ''srun'' output on a per parallel-task basis.

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===== Option 1 - Output only =====

Each task that is started by ''srun'' is given its own log file to capture any output it produces. The name of the log file will be **mytask.$HOSTNAME.$SLURM_ARRAY_TASK_ID.log**, where ''$HOSTNAME'' is the name of the node that Slurm started the job on, and ''$SLURM_ARRAY_TASK_ID'' is the number of the parallel task which Slurm has started.

e.g. ''mytask.node044.1.log'' 

<code lang=bash>
rm -f mytask.*.log
srun COMMAND >mytask.${HOSTNAME}.${SLURM_ARRAY_TASK_ID}.log
</code>

Any errors produced by the srun task __will still be captured__ by the **main Slurm output file**.

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===== Option 2 - Output and Errors =====

Each task that is started by ''srun'' is given its own log file to capture any output it produces. The name of the log file will be **mytask.$HOSTNAME.$SLURM_ARRAY_TASK_ID.log**, where ''$HOSTNAME'' is the name of the node that Slurm started the job on, and ''$SLURM_ARRAY_TASK_ID'' is the number of the parallel task which Slurm has started.

e.g. ''mytask.node044.1.log'' 

In addition, any error output produced by the srun task __will also be captured in the same log file__ as normal output, i.e. **the file named above**.

<code lang=bash>
rm -f mytask.*.log
srun COMMAND 2>&1 >task.${HOSTNAME}.${SLURM_ARRAY_TASK_ID}.log
</code>

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===== Option 3 - Output and Dedicated Errors log =====

Each task that is started by ''srun'' is given its own log file to capture any output it produces. The name of the log file will be **mytask.$HOSTNAME.$SLURM_ARRAY_TASK_ID.log**, where ''$HOSTNAME'' is the name of the node that Slurm started the job on, and ''$SLURM_ARRAY_TASK_ID'' is the number of the parallel task which Slurm has started.

e.g. ''mytask.node044.1.log'' 

Any errors produced by the srun task will be captured in a log file **of the same name**, but with the **''.err'' suffix**.

e.g. ''mytask.node044.1.err'' 

<code lang=bash>
rm -f mytask.*.log
rm -f mytask.*.err
srun COMMAND >task.${HOSTNAME}.${SLURM_ARRAY_TASK_ID}.log 2>task.${HOSTNAME}.${SLURM_ARRAY_TASK_ID}.err
</code>

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