sattach - Man Page

Attach to a Slurm job step.


sattach [options] <jobid.stepid>


sattach attaches to a running Slurm job step.  By attaching, it makes available the IO streams of all of the tasks of a running Slurm job step.  It also suitable for use with a parallel debugger like TotalView.


-h,  --help

Display help information and exit.

--input-filter[=]<task number>
--output-filter[=]<task number>
--error-filter[=]<task number>

Only transmit standard input to a single task, or print the standard output or standard error from a single task.  The filtering is performed locally in sattach.

-l,  --label

Prepend each line of task standard output or standard error with the task number of its origin.


Contacts the slurmctld to obtain the task layout information for the job step, prints the task layout information, and then exits without attaching to the job step.


Execute task zero in pseudo terminal. Not compatible with the --input-filter, --output-filter, or --error-filter options. Notes: The terminal size and resize events are ignored by sattach. Proper operation requires that the job step be initiated by srun using the --pty option.

-Q,  --quiet

Suppress informational messages from sattach. Errors will still be displayed.

-u,  --usage

Display brief usage message and exit.

-V,  --version

Display Slurm version number and exit.

-v,  --verbose

Increase the verbosity of sattach's informational messages.  Multiple -v's will further increase sattach's verbosity.


Executing sattach sends a remote procedure call to slurmctld. If enough calls from sattach or other Slurm client commands that send remote procedure calls to the slurmctld daemon come in at once, it can result in a degradation of performance of the slurmctld daemon, possibly resulting in a denial of service.

Do not run sattach or other Slurm client commands that send remote procedure calls to slurmctld from loops in shell scripts or other programs. Ensure that programs limit calls to sattach to the minimum necessary for the information you are trying to gather.

Input Environment Variables

Upon startup, salloc will read and handle the options set in the following environment variables.  Note: Command line options always override environment variables settings.


The location of the Slurm configuration file.


Specifies the exit code generated when a Slurm error occurs (e.g. invalid options). This can be used by a script to distinguish application exit codes from various Slurm error conditions.


Attach to job 15, step 0:
$ sattach 15.0
Limit the output to the 5th task of job 65386, step 15:
$ sattach --output-filter 5 65386.15


Copyright (C) 2006-2007 The Regents of the University of California. Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
Copyright (C) 2008-2009 Lawrence Livermore National Security.
Copyright (C) 2010-2013 SchedMD LLC.

This file is part of Slurm, a resource management program. For details, see <>.

Slurm is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

Slurm is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

See Also

sinfo(1), salloc(1), sbatch(1), squeue(1), scancel(1), scontrol(1), slurm.conf(5), sched_setaffinity (2), numa (3)

Referenced By

salloc(1), sbatch(1), slurm(1), srun(1).

February 2021 Slurm Commands