# Accessing Slurm Cluster

## The Merlin Slurm clusters

Merlin contains a multi-cluster setup, where multiple Slurm clusters coexist under the same umbrella.
It basically contains the following clusters:

* The **Merlin6 Slurm CPU cluster**, which is called [**`merlin6`**](#merlin6-cpu-cluster-access).
* The **Merlin6 Slurm GPU cluster**, which is called [**`gmerlin6`**](#merlin6-gpu-cluster-access).

## Accessing the Slurm clusters

Any job submission must be performed from a **Merlin login node**. Please refer to the [**Accessing the Interactive Nodes documentation**](accessing-interactive-nodes.md)
for further information about how to access the cluster.

In addition, any job *must be submitted from a high performance storage area visible by the login nodes and by the computing nodes*. For this, the possible storage areas are the following:

* `/data/user`
* `/data/project`
* `/shared-scratch`

Please, avoid using `/psi/home` directories for submitting jobs.

### Merlin6 CPU cluster access

The **Merlin6 CPU cluster** (**`merlin6`**) is the default cluster configured
in the login nodes. Any job submission will use by default this cluster, unless
the option `--cluster` is specified with another of the existing clusters.

For further information about how to use this cluster, please visit: [**Merlin6 CPU Slurm Cluster documentation**](../slurm-configuration.md).

### Merlin6 GPU cluster access

The **Merlin6 GPU cluster** (**`gmerlin6`**) is visible from the login nodes. However, to submit jobs to this cluster, one needs to specify the option `--cluster=gmerlin6` when submitting a job or allocation.

For further information about how to use this cluster, please visit: [**Merlin6 GPU Slurm Cluster documentation**](../../gmerlin6/slurm-configuration.md).