Access

Cluster Connections

How to connect to the cluster with a PC?

TTS research servers require an ssh connection to a host providing shell access. Use of Cygwin ssh, SecureCRT, Putty, etc... will work. Other forms of connection such as XDM, rsh, rlogin, telnet are not supported.

How may I connect to the cluster if I don't have a computer?
There are many computer labs on campus that you may use.

What connection protocols are supported on the cluster?

ssh, ssh2, sftp, scp

If I am using command line ssh and scp, how do I transfer files back and forth?

A special transfer host, xfer.cluster.tufts.edu, should be used to transfer files to and from a remote computer.

For example...

To copy a file up to the cluster into your home dir(user John Doe):
> scp your_file.xyz jdoe02@xfer.cluster.tufts.edu:/cluster/home/j/d/jdoe02/

To copy a file down to your PC or laptop into your current dir:
> scp jdoe02@xfer.cluster.tufts.edu:/cluster/home/j/d/jdoe02/your_file.txt .

Note the period on the end indicates in the current directory

Most users are more likely to use a gui-based file transfer program such as Winscp. It is freely available.

What about ftp and ncftp?
The cluster does not run a ftp server, so you can't ftp to the cluster. Instead you should use sftp and scp clients on your desktop.

Suppose I wish to transfer data to a site that requires ftp?
ftp and ncftp clients on the cluster are available for transferring data to sites that require ftp.

How to connect to the cluster with a Mac?

Open an xterm window and use ssh.

ssh -YC   jdoe02@login.cluster.tufts.edu

Provide your Tufts username and password (same as your email).

How to connect to the cluster under Linux?

Open a local shell window or xterm and connect with:

> ssh -YC jdoe02@login.cluster.tufts.edu

Provide your username and password (same as your email).

Can I connect to the cluster from home or while I am traveling?

Yes, use an ssh based login solution such as ssh, etc...

Do I need SecureCRT to connect to the cluster?

No, if you use Cygwin you do not need SecureCRT. If you choose to use it, you will likely need a windows based X server such as Exceed or Xwin32 or similar if you expect to display graphics.

Can I get SecureCRT from Tufts?
Yes, but use Cygwin instead. SecureCRT Information can be found on the TTS website .

How does one connect to the cluster with an Android tablet?
In general you will need an ssh based application. Try ConnectBot or JuiceSSH available on Google Play.

How does one connect to the cluster with an iPad?
In general you will need an ssh based application. There are dozens of ssh clients. Try iSSH. By many accounts it is considered one of the leading contenders.

When connected to the cluster with ssh I sometimes get disconnected after a period of idle use. How do I remain connected?

On a linux machine, your home directory will contain a .ssh subdirectory. Create a text file called config with the following contents:

host * ServerAliveInterval 120

If you are using some other ssh based client, look for a setup option where you can choose or include this info.

X Window support info

What is X11 forwarding?
ssh provides a protocol for sending X11 graphics between computers. This option needs to be turned on within your ssh program, such as SecureCRT or ssh command option, etc. If you use SecureCRT you need to enable X11 forwarding. Look for this option in your SecureCRT preference or global settings.

Why is an Xserver needed?
This software is needed if you wish to display on your PC or Mac, windows generated by an application such as Matlab, running on the cluster.

Where can I get more info about Xservers?
Visit the link X based graphics FAQs on the first page of this wiki.

How can I install Cygwin for X11 window support?
This linked page for cygwin will walk you through the steps.

How do I connect to the cluster from the Blake Computational Studio in Anderson Hall?

Blake Lab is currently configured to use WinScp for transferring files between your Windows account and the cluster.

For ssh and X11 needs there is a linux virtual(program) running on lab PCs. Just login to one of the Blake systems and click on the linux icon on the desktop. It automatically boots into guest mode. Once established a terminal window should start up automatically. From there you can login to the cluster with ssh:

ssh -Y -C UTLN@login.cluster.tufts.edu

Make sure x11 over ssh works by typing xlogo at the cluster shell prompt.
This should bring up a small window with an X inside of it.

From this point you can start any of the cluster applications as one would normally do.

If you have any questions on getting to the cluster from Blake Lab PCs or your own laptop/desktop, contact cluster-support@tufts.edu
Arrangements can be made to obtain a linux virtual solution for X11 support.

I am unable to log onto the cluster despite having a valid UTLN. The message I see is that I am being rejected. This worked before, what can I do?

It is likely that your IP address is blocked by the cluster. It may be that you have the wrong password. Otherwise you may have to visit the following site to find out what your remote IP address is so that we can unblock it. There are many reasons why this might be the case. Copy the IP addresses displayed there and send it back to us via the cluster support email venue, tts-support@tufts.edu with an explanation.