Download and setup MobaXterm¶
To access the VSC clusters with MobaXterm you need to have an SSH key pair. You can use the key pair previously generated with PuTTY or generate a new key pair with MobaXterm.
Go to the MobaXterm website and download the
free version. Make sure to select the Portable edition from the download
page. Create a folder called
MobaXterm in a known location in your computer and
decompress the contents of the downloaded zip file inside it.
Setup a shortcut for a remote session¶
Double click the
MobaXterm_Personalexecutable file inside the
MobaXtermfolder. The MobaXterm main window will appear on your screen. It should be similar to this one:
Click on the Session icon in the top left corner.
The Session settings configuration panel will open; click on the SSH icon in the top row and you should see a window like this:
In the Remote host field introduce the cluster remote address of your VSC cluster, which should be written in the form
my-vsc-cluster.example.com. Tick the Specify username box and introduce your VSC account username. Click the Advanced SSH settings tab and you will see these extra options:
Tick the Use private key box and click on the file icon in that field. A file browser will be opened; locate the private SSH key file you created when requesting your VSC account. Please keep in mind that these settings have to be updated if the location of the private SSH key ever changes. Check that the SSH-browser type is set as SFTP protocol.
Press the OK button and you should be prompted for your passphrase. Enter here the passphrase you chose while creating your public/private key pair. The characters will be hidden and nothing at all will appear as you type (no circles, no symbols). You should connect to the cluster and be greeted by a screen similar to this one:
On the left sidebar (in the Sftp tab) there is a file browser of your home directory in the cluster. You will see by default many files whose names start with a dot (.) symbol. These are hidden files of the Linux environment and you should not delete nor move them. You can hide the hidden files by clicking on the right most button at the top of the file browser.
Once you disconnect from the cluster (by typing
exitor closing the terminal tab) you will find on the left sidebar (in the Sessions tab) a shortcut to the session you just setup. From now on, when you open MobaXterm, you can just double click that shortcut and you will start a remote session on the VSC cluster that you used in previous steps.
To create a direct shortcut on your desktop (optional), right click on the saved session name and choose Create a desktop shortcut (see image below). An icon will appear on your Desktop that will start MobaXterm and open a session in the corresponding cluster.
Now you can create connections to other VSC clusters by repeating these steps and changing the address of the cluster. You will have then a shortcut on the Sessions tab of the left sidebar for each of them to connect to.
Copying files to and from the cluster¶
Once you’ve setup the shortcut for connecting to a cluster, as we noted in step 6 of the previous section, you will see on the left sidebar (in the Sftp tab) a file browser on the cluster you are connected to.
You can simply drag and drop files from your computer to that panel and they will be copied to the cluster. You can also drag and drop files from the cluster to your computer. Alternatively, you can use the file tools located at the top of the file browser.
Remember to always press the
Refresh current folder button after you
copied something or created/removed a file or folder on the cluster.
Setup an SSH agent to avoid typing the passphrase at each login¶
Once you’ve successfully setup the connection to your cluster, you will notice that you are prompted for the passphrase at each connection you make to a cluster. To avoid retyping it each time, you can setup an internal SSH agent in MobaXterm that will take care of unlocking the private key when you open the application. The SSH agent will save the passphrase after you have introduced it once.
Open the MobaXterm program and go to the menu Settings -> Configuration
You should see the MobaXterm Configuration panel. In the General tab choose the MobaXterm passwords management option; a new panel will be opened; make sure that Save sessions passwords has the options Always and Save SSH keys passphrases as well selected (as shown below) and click OK.
Open the SSH tab in the same MobaXterm Configuration panel. Make sure that all the boxes below the SSH agents section are ticked.
Press the + button in the Load following keys at MobAgent startup field, look for your private key file and select it. At the end of the process, the panel should look like this (the location of your private SSH key may be different):
Please, keep in mind that these settings will have to be updated if the location of private key ever changes.
Press OK and when prompted for restarting MobaXterm, choose to do so.
Once MobaXterm restarts you will be asked for the private key passphrase at launch. This will occur only once and after you introduce it correctly it will stay saved for all following sessions. Double clicking on a shortcuts for a cluster should open the corresponding connection directly.
Troubleshooting MobaXTerm connection issues¶
If you have trouble accessing the infrastructure, the support staff will likely ask you to provide a log. After you have made a failed attempt to connect, you can obtain the connection log by
ctrl-right-clicking in the MobaXTerm terminal and selecting Event Log.
In the dialog window that appears, click the Copy button to copy the log messages. They are copied as text and can be pasted in your message to support.