> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nyc-ai.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Quickstart

> Your first SLURM job on CUNY HPCC, start to finish.

This walkthrough takes you from a fresh HPCC account to a running job in about ten minutes. You'll log in, load a module, submit a minimal SLURM job, and read its output.

<Info>
  **Prerequisites:** An approved HPCC account. If you don't have one, start with [Accounts & access](/accounts-access).
</Info>

## Step 1: Log in

From your laptop, SSH to the Chizen gateway and then onto the cluster you want to use (Arrow is the default for most users):

```bash theme={null}
ssh <your_username>@chizen.csi.cuny.edu
ssh <your_username>@arrow
```

<Tip>
  If you're off-campus and connections fail, confirm you're reaching an externally accessible gateway (**Chizen** or **Karle** only). All other systems require you to go through one of those first.
</Tip>

## Step 2: Check your storage

Home and scratch are separate. Home is small and durable; scratch is larger and temporary. Check both:

```bash theme={null}
df -h ~                    # your home directory (/global/u/<username>)
df -h /scratch/$USER       # your scratch workspace
```

The default home quota is **50 GB / 10,000 files**. Jobs **must** run out of scratch; don't launch from your home directory.

See [Storage & quotas](/storage) for full details.

## Step 3: Find a module

The HPCC uses the **LMOD** environment module system on Arrow. Browse what's available:

```bash theme={null}
module avail            # list all available modules
module spider python    # search for Python variants and their dependencies
module list             # show what's currently loaded
```

Load the module you want:

```bash theme={null}
module load Python/3.10.4       # exact version string may differ; check module avail
```

See [Software & modules](/software-modules) for the full workflow.

## Step 4: Write your first SLURM script

Move to your scratch directory and create `hello.sh`:

```bash theme={null}
cd /scratch/$USER
mkdir -p hello-slurm && cd hello-slurm
```

```bash hello.sh theme={null}
#!/bin/bash
#SBATCH --job-name=hello
#SBATCH --output=hello.out
#SBATCH --error=hello.err
#SBATCH --nodes=1
#SBATCH --ntasks=1
#SBATCH --cpus-per-task=1
#SBATCH --mem-per-cpu=1G
#SBATCH --time=00:01:00

cd $SLURM_SUBMIT_DIR
echo "Hello from $(hostname) - job $SLURM_JOB_ID"
sleep 5
echo "Done."
```

<Warning>
  The minimal template above omits `--qos` and `--partition`, which real HPCC jobs typically require (for example `--qos=qoschem --partition=partchem`). Ask your PI or the [HPC Helpline](mailto:HPCHelp@csi.cuny.edu) which QOS / partition applies to your project before submitting production work.
</Warning>

## Step 5: Submit and monitor

```bash theme={null}
sbatch hello.sh          # submit; prints the job ID
squeue -u $USER          # see your jobs in the queue
scancel <jobid>          # cancel if needed
```

Once the job completes, the `hello.out` file in your working directory will contain the output.

```bash theme={null}
cat hello.out
```

## What next

<CardGroup cols={2}>
  <Card title="More SLURM examples" icon="play" href="/job-submission">
    OpenMP, MPI, hybrid, GPU, and array templates.
  </Card>

  <Card title="Software & modules" icon="boxes-stacked" href="/software-modules">
    Load compilers, MPI libraries, Python, Julia, and more.
  </Card>

  <Card title="Storage & transfers" icon="database" href="/storage">
    Move data in and out with SFTP, Globus, or iRODS.
  </Card>

  <Card title="Policies" icon="shield-halved" href="/policies">
    Rules every HPCC user needs to follow.
  </Card>
</CardGroup>