This command forwards the standard output and error messages

 

from the running job with SLURM ID 6543 to the attaching srun

 

command to reveal the job’s current status, and (with -j) also joins

 

the job so that you can send it signals as if this srun command had

 

initiated the job. Omit -j for read-only attachments. Because you

 

are attaching to a running job whose resources have already been

 

allocated, the srun resource-allocation options (such as -N) are

 

incompatible with -a.

Batch (with LSF)

You can submit a script to LSF that contains (simple) srun

 

commands within it to execute parallel jobs later. In this case, LSF

 

takes the place of the srun -boption for indirect, across-machine

 

job-queue management.

6.4.2 srun Signal Handling

Signals sent to srun are automatically forwarded to the tasks that srun controls, with a few special cases. srun handles the Ctrl/C sequence differently, depending on how many times it receives Ctrl/C in one second. The following defines how Ctrl/C is handled by srun:

•If srun receives one Ctrl/C, it reports the state of all tasks associated with srun.

•If srun receives a second Ctrl/C within one second, it sends the SIGINT signal to all associated srun tasks.

•If srun receives a third Ctrl/C within one second, it terminates the job at once, without waiting for remote tasks to exit.

6.4.3srun Run-Mode Options

This section explains the mutually exclusive srun options that enable its different run modes.

-b (--batch)

This option runs a script in batch mode. The script name must appear at the end of the srun execute line, not as an argument to -b. You cannot use -bwith -Aor -a.

srun copies the script, submits the request to run (with your specified resource allocation) to the local SLURM-managed job queue, and ends. When resources become available and no higher priority job is pending, SLURM runs the script on the first node allocated to the job, with stdin redirected from /dev/null and stdout and stderr redirected to a file called jobname.out in the current working directory (unless you request a different name or a more elaborate set of output files by using -Jor -o).

The -boption has the following script requirements:

•You must use the script’s absolute pathname, or a pathname relative to the current working directory (srun ignores your search path).

•srun interprets the script using your default shell unless the file begins with the character pair #! followed by the absolute pathname of a valid shell.

•The script must contain MPI commands or other (simple) srun commands to initiate parallel tasks.

-A (--allocate)

The-Aoption allocates compute resources (as specified by other srun options) and starts (spawns) a subshell that has access to those allocated resources. No remote tasks are started. You cannot use -Awith -bor -a.

6-4Using SLURM