Accessing the Cluster

In this section:

Access via Linux/Unix/macOS
Access via Microsoft Windows
- PuTTY Configuration
- WinSCP Configuration
Security Confirmation
- First Access
- Server Key Change
Access Troubleshooting
- Connection Refused
- Permission Denied

GridUnesp runs on the Linux operating system and allows remote access via secure SSH (Secure Shell) connection. This section explains how to establish this connection from different operating systems.

Important

The server access.grid.unesp.br is exclusively for:

Accessing your account
Preparing scripts and files
Submitting jobs with sbatch

DO NOT run simulations on this server. Jobs must be submitted for execution on the processing nodes.

Access via Linux/Unix/macOS 

On Unix-based systems (Linux, macOS), use the terminal:

Access command

ssh your_username@access.grid.unesp.br

Replace your_username with the login chosen during registration (see Registration).

Access via Microsoft Windows 

On Windows, you need to install an SSH client. We recommend:

PuTTY (terminal)
WinSCP (file transfer)

PuTTY Configuration 

Fill in the fields:

Host Name: access.grid.unesp.br
Port: 22
Connection type: SSH

Click Open. A terminal window will open asking for your login and password.

WinSCP Configuration 

Fill in the fields:

File protocol: SCP
Host name: access.grid.unesp.br
Port number: 22
User name: Your GridUnesp login
Password: Your GridUnesp password

Click Login. The interface will show:

Left side: your local computer
Right side: your /home/ directory on GridUnesp

To open the terminal, click the black square icon in the top toolbar.

Security Confirmation 

First Access 

When connecting for the first time, the SSH client will display a message similar to:

The authenticity of host 'access.grid.unesp.br (200.145.46.48)' can't be established.
ED25519 key fingerprint is SHA256:+HEvFMmo0EA6ipPMJSaj5+Q6IabebRN+nRD0nxdYrKQ.
Are you sure you want to continue connecting (yes/no)?

Verify that the fingerprint matches one of the fingerprints below:

RSA:     SHA256:X3iCb13fWj7u2Tvp/MCCpn0brfSNS5Ie6ehm6lsvPSQ
ECDSA:   SHA256:WVFokXOLnuH9+2e7xxRU2gp7XJqxwuE6H8bbUMqTCXo
ED25519: SHA256:+HEvFMmo0EA6ipPMJSaj5+Q6IabebRN+nRD0nxdYrKQ

If it matches, type yes and press Enter.

Tip

To verify the keys at any time:

ssh-keyscan access.grid.unesp.br | ssh-keygen -lf -

Server Key Change 

If you have not accessed the cluster in a long time, you may encounter an error like:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

This happens when the server key changes (for example, after maintenance). To resolve it:

On Linux:

ssh-keygen -f "/home/your_local_user/.ssh/known_hosts" -R "access.grid.unesp.br"

On Mac:

ssh-keygen -f "/Users/your_local_user/.ssh/known_hosts" -R "access.grid.unesp.br"

Warning

your_local_user is the login on your personal computer, not your GridUnesp login.

After removing the old entry, try connecting again.

Access Troubleshooting 

Connection Refused 

ssh: connect to host access.grid.unesp.br port 22: Connection refused

Likely cause: Blocked by the Fail2Ban system after multiple attempts with incorrect passwords or excessive SCP use. Check details on the section User Lockout (Fail2Ban).

Solution: Wait 15 minutes and try again.

Permission Denied 

Permission denied, please try again.

Possible causes:

Incorrect password
Incorrect username
Locked account

Solutions:

Verify that the username is correct
If you forgot your password, reset it at: https://www.ncc.unesp.br/password-new/
If the problem persists, contact support (support.ncc@unesp.br)