Introduction to Slurm¶

Getting Started¶

For a general introduction to Slurm — including an overview of its architecture, key commands (sinfo, squeue, srun, sbatch, scancel, scontrol), and basic job submission examples — refer to the official Slurm Quick Start User Guide. The guide is well-maintained and covers the core concepts you need to get up and running.

The sections below supplement that guide with information specific to CARC Easley at the University of New Mexico.

CARC Easley Partitions¶

When you run sinfo on Easley, you will see output similar to the following:

[username@easley ~]$ sinfo

PARTITION   AVAIL  TIMELIMIT  NODES  STATE NODELIST
general*       up 2-00:00:00      1   comp easley002
general*       up 2-00:00:00      4   mix- easley[008,015,018,044]
general*       up 2-00:00:00      8    mix easley[003-004,012-014,016,020,023]
general*       up 2-00:00:00     34  alloc easley[001,005-007,009-011,017,019,021-022,024-043,046-048]
general*       up 2-00:00:00      1   down easley045
bigmem         up 2-00:00:00      1    mix easley050
bigmem         up 2-00:00:00      1  alloc easley049
h100           up 2-00:00:00      1   mix- easley051
h100           up 2-00:00:00      1   plnd easley054
h100           up 2-00:00:00      2  alloc easley[052-053]
l40s           up 2-00:00:00      1    mix easley055
l40s           up 2-00:00:00      2  alloc easley[056-057]
interactive    up    4:00:00      1   comp easley002
interactive    up    4:00:00      5   mix- easley[008,015,018,044,051]
interactive    up    4:00:00      1   plnd easley054
interactive    up    4:00:00     10    mix easley[003-004,012-014,016,020,023,050,055]
interactive    up    4:00:00     39  alloc easley[001,005-007,009-011,017,019,021-022,024-043,046-049,052-053,056-057]
interactive    up    4:00:00      1   down easley045
debug          up    1:00:00      1   comp easley002
debug          up    1:00:00      5   mix- easley[008,015,018,044,051]
debug          up    1:00:00      1   plnd easley054
debug          up    1:00:00     10    mix easley[003-004,012-014,016,020,023,050,055]
debug          up    1:00:00     39  alloc easley[001,005-007,009-011,017,019,021-022,024-043,046-049,052-053,056-057]
debug          up    1:00:00      1   down easley045
scavenger      up 2-00:00:00      1   comp easley002
scavenger      up 2-00:00:00      9   mix- easley[008,015,018,044,051,060-063]
scavenger      up 2-00:00:00      1   plnd easley054
scavenger      up 2-00:00:00     10    mix easley[003-004,012-014,016,020,023,050,055]
scavenger      up 2-00:00:00     41  alloc easley[001,005-007,009-011,017,019,021-022,024-043,046-049,052-053,056-059]
scavenger      up 2-00:00:00      1   down easley045

Key partitions on Easley (limits as observed 2026-07-25 — sinfo or scontrol show partition <name> always shows the current values):

• general — The default community partition. Maximum wall time of 2 days.
• bigmem — Two large-memory nodes (about 2 TB of RAM each) for jobs that need far more memory than a general node provides. Maximum wall time of 2 days.
• h100 — GPU nodes with 2× NVIDIA H100 per node. Maximum wall time of 2 days.
• l40s — GPU nodes with 4× NVIDIA L40S per node. Maximum wall time of 2 days.
• interactive — Interactive sessions of up to 4 hours, scheduled at elevated priority.
• debug — Short test jobs only (1-hour limit — note the 1:00:00 in the sinfo output above). Useful for checking scripts before submitting long runs.
• scavenger — Runs on reserved nodes whenever they sit idle. Open to everyone, but preemptible: your job is killed if the owner submits work.
• liulab — A lab-restricted partition (7-day limit) belonging to a specific research group.

To see detailed node information including CPU count, memory, and disk:

sinfo -N -l

If you omit --partition (or -p) from your job submission, your job will be submitted to the general partition by default.

Useful squeue Flags¶

The official guide covers squeue basics. A few flags that are especially handy on a shared cluster:

squeue --me              # Show only your jobs
squeue -p general        # Show only jobs in the general partition
squeue -u <username>     # Show jobs for a specific user

Canceling Jobs¶

scancel <JOBID>          # Cancel a specific job
scancel --me             # Cancel all of your jobs

Notes on Resource Requests¶

• The more constraints you add to a job (e.g., requiring all tasks on the same node with --ntasks-per-node), the longer your queue time may be. Requesting resources spread across nodes often results in faster scheduling.
• Memory is specified per CPU with --mem-per-cpu (in MB) or for the whole job with --mem.
• Time limits use the format D-HH:MM:SS (e.g., 1-12:00:00 for 1 day and 12 hours) or MM:SS / HH:MM:SS for shorter jobs.
• If you omit --time, you do not get the partition maximum: general applies a default of 8 hours (DefaultTime=08:00:00). Check scontrol show partition <name> for the partition you use.
• If you omit --mem/--mem-per-cpu, memory defaults to an amount proportional to the CPUs you request (DefMemPerCPU — observed ≈3.7 GB per CPU on Easley's general partition, ≈2.9 GB on Hopper's). A small --cpus-per-task therefore caps your memory well below what the node physically has — the usual cause of jobs killed OUT_OF_MEMORY on nodes with plenty of free RAM. See troubleshooting.

Additional Resources¶

• Official Slurm Quick Start Guide
• CARC at UNM Documentation
• For help, contact the CARC support team or visit the CARC user portal.

This quickbyte was validated on 6/22/2026.

Video walkthrough¶

Slurm Job Scheduler — from the CARC video tutorials:

Migrated from UNM-CARC QuickBytes (last source update 2026-07-06). Spotted a problem? Open an issue or pull request.