# Introduction

!!! failure "Deprecated"
    Merlin6 is no longer accessible for new users! Please have a look at
    [Merlin 7](../merlin7/01-Quick-Start-Guide/introduction.md) instead.

## Slurm clusters

Comprised the **`merlin6`** CPU cluster and the
[**`gmerlin6`**](../gmerlin6/cluster-introduction.md) GPU cluster. A legacy
cluster (formally called [**`merlin5`**](../merlin5/cluster-introduction.md) is
kept active with best effort support.

From July 2019, **`merlin6`** becomes the **default Slurm cluster** and any job
submitted from the login node will be submitted to that cluster if not.

* Users can keep submitting to the old *`merlin5`* computing nodes by using the option ``--cluster=merlin5``.
* Users submitting to the **`gmerlin6`** GPU cluster need to specify the option ``--cluster=gmerlin6``.

### Slurm 'merlin6'

**CPU nodes** are configured in a **Slurm** cluster, called **`merlin6`**, and
this is the ***default Slurm cluster***. Hence, by default, if no Slurm cluster
is specified (with the `--cluster` option), this will be the cluster to which
the jobs will be sent.