Basic Account and Software Setup

Last update: 06 Nov 2020 [History] [Edit]

These pages intend to get you set up for the software tutorial week and make sure you are ready for your work on ATLAS.

Initial Login

You can run the tutorial hands-on sections using either option:

(A) lxplus, or

(B) Tier3 machine (a site, your own laptop, or the CernVM guest machine). You may first want to ensure that you are able to do password-less logins or preferably Kerberos authentications to these machines. Instructions to do this can be found here.

As of November 2020, we strongly suggest you use lxplus for the purpose of this tutorial

However, below you will find instructions for either lxplus or the tier3 option, choose one. There may be problems with using some of the tier3 sites for analysis, it is difficult to test everything! In theory though, they should be a viable option.

On lxplus

These machines are ATLAS ready and you do not have to install additional software.

To log into lxplus you should type:

ssh -Y -l <username> lxplus.cern.ch

Go to resources.web.cern.ch/resources/ and select List Services (top). In the search box type “afs”. You should see a link called “AFS Workspaces” appear. Click on the link.
Select “Settings” in the left menu, and you should find that you are able to increase your quota for both you home area and workspace area.

This is granted by increments so if you click it several times, you can get the maximum allowed quota.

You can use either your home or workspace area for the tutorial.

To check X11 forwarding is done correctly (the -Y part after ssh) type something like xterm.

At Tier3s

Check that your machine is ATLAS-ready. If you are managing your machine, the minimal requirements are

  • CVMFS is installed, mounted and working but otherwise this will be checked in the next sections.

Login to your Tier3 (if you are not already logged on) with the -Y option so that your X-windows are exported back.

ssh -Y -l <username> <your tier3 hostname>

To check X11 forwarding is done correctly (the -Y part after ssh) type something like xclock or xlogo.