---
name: "sattach"
section: "1"
platform: "linux"
package: "slurm-llnl"
version: "26.05.5.1-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/sattach"
---

# sattach(1)

Attach to a Slurm job step.

## NAME

sattach - Attach to a Slurm job step.

## SYNOPSIS

sattach \[*options*\] \<jobid\|sluid)\>.\<stepid\>

## DESCRIPTION

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 is also suitable for use with a parallel debugger like TotalView. It cannot be used to attach directly to extern or batch steps since the IO channels of these steps are not set or directly forwarded to a file.

A SLUID may be used in place of a numeric job ID to identify the job.

## OPTIONS

- **--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.

-

  - **-h**, **--help**

  Display help information and exit.

-

  - **--input-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.

-

  - **--layout**

  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.

-

  - **--output-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.

-

  - **--pty**

  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.

-

  ## PERFORMANCE

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.

- **SLURM\_CONF**

  The location of the Slurm configuration file.

-

  - **SLURM\_DEBUG\_FLAGS**

  Specify debug flags for sattach to use. See DebugFlags in the [**slurm.conf**(5)](/slurm.conf/5.md) man page for a full list of flags. The environment variable takes precedence over the setting in the slurm.conf.

-

  - **SLURM\_EXIT\_ERROR**

  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.

-

  ## EXAMPLES

- Attach to job 15, step 0:

  -

  ```
  $ sattach 15.0
  ```

- Attach to job with SLUID s4SNKN57XZTE00, step 1:

  -

  ```
  $ sattach s4SNKN57XZTE00.1
  ```

- Limit the output to the 5th task of job 65386, step 15:

  -

  ```
  $ sattach --output-filter 5 65386.15
  ```

## COPYING

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) 2010-2022 SchedMD LLC.

This file is part of Slurm, a resource management program. For details, see \<https://slurm.schedmd.com/\>.

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)](/sinfo/1.md), [**salloc**(1)](/salloc/1.md), [**sbatch**(1)](/sbatch/1.md), [**squeue**(1)](/squeue/1.md), [**scancel**(1)](/scancel/1.md), [**scontrol**(1)](/scontrol/1.md), [**slurm.conf**(5)](/slurm.conf/5.md), **sched\_setaffinity** (2), **numa** (3)