Connecting to the cluster

You can connect to the cluster via ssh from the Sapienza network or through Sapienza's VPN. To do this, you will need to get an account.

Pre-requisites¶

Having an account on the cluster¶

In order to connect to the cluster, you will need to use your account. It can be created by a group leader (e.g. your supervisor) or an admin. If you're in doubt or want to become a group leader, ask an admin.

If you're a group leader or an admin and want to create an account, you have to simply use the add_user_hpc on the frontend node:

add_user_hpc

Output of the add_user_hpc command

The output will be something like that:

You're about to create a new user in the cluster. There exists three kinds of users:
1) Students: have access to a subset of nodes in the cluster
2) Department: have access to all nodes in the cluster
3) Group leaders: like department, but can create new users. It can be created only by admins, so contact cluster.di@uniroma1.it
Which kind of user are you adding? (students, department)
students
What is the name of the new department user?
new_user
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
make[1]: Entering directory '/var/yp/frontend.nis.htc'
Updating passwd.byname...
Updating passwd.byuid...
Updating group.byname...
Updating group.bygid...
Updating netid.byname...
Updating shadow.byname...
make[1]: Leaving directory '/var/yp/frontend.nis.htc'
User 'new_user' has been successfully created.

Being connected to the Sapienza network¶

The cluster will be accessible only if your connection is part of the Sapienza network. There are three possibilities to accomplish this.

Through Sapienza wifiThrough Sapienza VPNThrough Department's VPN

If you're connected to the sapienza or eduroam wifi networks from inside the university, then you're all set.

If you're physically outside of the university, then you can connect to the Sapienza VPN.

This is only possible if you have a @uniroma1.it email, and so if you're a PhD student, researcher or professor.

If you're both physically outside of the university and don't have a @uniroma1.it email (e.g. you're a student), then you can connect using Department's VPN and your institutional credentials.

Note that using this VPN lets you direct access to the submitter node, so you can bypass the frontend hop.

Connect to the cluster¶

For this to work, you have to first connect to the frontend node, and from there to th submitter node, where you can use Slurm.

To connect to the frontend server, you can use ssh to the address 151.100.174.45:
```
ssh <user>@151.100.174.45
```
Make sure to replace <user> with your username, and make sure to be connected to the Sapienza network.
Once you're in the frontend node, you have to ssh again into the submitter node:
```
ssh submitter
```
Once there, you can use Slurm.

Connect in a single step

If you're using Linux, you can connect in a single step like this:

ssh -J <user>@151.100.174.45 <user>@submitter