MjolnirDocumentation
Monitoring Jobs guide current Reviewed 2026-09-02

Cancelling jobs

A normal job#

bash
scancel <jobid>

One task in an array#

bash
scancel <arrayjobid>_<taskid>

For example, scancel 1234567_7 cancels only task 7 — the rest of the array keeps running.

An entire array#

bash
scancel <arrayjobid>

scancel 1234567 cancels every task in that array, whether pending or already running.

What actually happens#

scancel requests termination — it doesn't guarantee an instant stop. A running job is sent a signal and Slurm gives it a short window to exit before forcing it; a pending job is simply removed from the queue. Either way, the job's state may take a few moments to settle — a job you just cancelled can briefly still show up in squeue.

bash
squeue -j <jobid>

An empty result means the job is gone. sacct will show it as CANCELLED:

bash
sacct -j <jobid> --format=JobID,State,ExitCode

Note Cancelling doesn't delete anything. Any output already written by your program stays on disk exactly as it was when the job stopped — this is a property of your program, not of scancel. Whether a partial result is usable depends on what your program was doing when it was cut off; some produce a clean partial file, others don't.

When to cancel#

Common, reasonable reasons:

  • You submitted with the wrong input file or the wrong arguments
  • You requested the wrong resources (see Submitting jobs)
  • You accidentally submitted a duplicate
  • You submitted an array larger than intended
  • The job is clearly stuck — no progress, no output, far past when it should have finished
  • You simply don't need the result anymore

Warning Cancelling and resubmitting repeatedly is not a way to improve your place in the queue — fairshare and priority work the same regardless, and doing this just adds churn. If a job is pending for a reason you can't resolve yourself, see Why is my job pending? instead.