LHC@home: Test4Theory

The computing needs of the LHC, especially when it comes to comparing various theories with experimental results, are enormous. Basically, the physicists' appetite for computing power expands to fill all available resources, because there are always more theories to test than there are computers to test them with.

Since budgets are constrained, especially in these economically difficult times, access to volunteer resources is seen by CERN as a great opportunity to expand computing capacity. We'll never replace the Grid's core function of managing the data mountains, but we could augment its computing power considerably. Test4theory is a first step in that direction.

It's also clear to everyone in our community that getting the public more directly involved in LHC physics has great outreach benefits as well. So we see this as a win-win situation. And who knows, perhaps one day we'll be able to announce an important discovery that will have been made in part thanks to the volunteers. That would be cool!

In this FAQ and by all means asking and participating in the message boards of the project. We have a great community that will try to help you.

You need a computer connected to the Internet with at least 512MB of RAM and 9GB of free hard disk space. It can run Windows, MacOSX or Linux. Additionally you will have to install two applications: BOINC and VirtualBox. Please, read carefully our installation guide.

For the moment this project does not use GPUs for running the experiments. Additionally, the GPU code could not work as we are accessing the hardware via a virtual machine.

We know it, and for this reason we are working together with the BOINC and VirtualBox communities to simplify the whole process to set up the software and join us. It will be interesting if you can tell us where you have difficulties, please use the forums, so we can try to fix them for the next releases.

You will only have to provide a user name and an e-mail, nothing else is required. The information that is sent about your machine is the hardware specifications: CPU type, RAM and disk space, OS version, etc.

The BOINC transfer at most network preference is not supported for the moment. If your ISP has a limitation in the bandwidth that you can use each month, bear in mind that the virtual machine will continue downloading/uploading data when needed.

You will be helping scientists by running simulations of particle collisions on your home computer. If you are interested in the details, please read the full explanation of the project.

We are already processing real data which is submitted to a central database. Please, see the full explanation of the project experiments.

If you want to see what is going on in the Virtual Machine, you have two options:

• Since wrapper version 7.04 and cernvm 2.4.1 (released the 16th of January of 2012), you can access the results, figures BOINC stats and logs of the experiments within the VM loading a friendly web page: http://localhost:7859/ in your web browser, or
• you only have to click inside the BOINC_VM window and then, change to the second terminal pressing ctrl-alt-F2 (this changes between OSes, please read the debugging page).

In this terminal or in the web application you will see the output of different Monte Carlo event generators (Herwig++, Pythia 6, Pythia 8, Sherpa, Vincia).

All the work units are designed to run for a fixed period of time of 24 hours. The difference appears in the amount of work done inside the virtual machine.

We are using Herwig++, Pythia 6, Pythia 8, Sherpa and Vincia.

We recommend to stop first BOINC before suspending, hibernating or powering off the computer, because VirtualBox will capture that signal, and will try to stop first the virtual machine, canceling the WU.

Yes, you can see all the results in a friendly web application which is provided in the virtual machine. In order to see the results you will have to open the following web page: http://localhost:7859/ Here you have an screenshot of it up and running:

There could be several possible options for this error, primarily:

(i) VirtualBox is not installed in your computer or

(ii) you have found a new bug in the system.

Some Windows XP users are reporting that by installing Visual C++ 2005 Redistributable Package the project starts working again. You can download this package for 32 bits from here and for 64 bits from here. These packages are official Microsoft solutions and they are free.

If you do have VirtualBox installed, review the FAQ and then ask in the message boards for help, so developers can review the error and help you.

VirtualBox has two access methods:

• VBoxManage: the command line interface for the VirtualBox hypervisor.
• VirtualBox Manager: a front-end GUI interface for the VirtualBox hypervisor.

The T4T wrapper uses the VBoxManage command line interface to control the task's Virtual Machine (register, stop, pause, save state, etc.).

The VirtualBox Manager interface is designed for users, and offers a view of all the VM's currently registered on the user's machine (including the T4T VM which is called "BOINC_VM").

We believe that VirtualBox versions before 4.1 have a problem if the Manager is open at the same time as the BOINC project runs. The problem is that while the wrapper is performing its tasks with the VM using the VBoxManage command, the Manager is not updated accordingly, and this can cause a WU to fail. (For example, imagine that you have the Manager opened at the end of a T4T task. You will see that the VM state changes from "Running". The wrapper will stop the VM and try to remove it, however for the Manager the VM is still registered. Thus, the next incoming WU will fail when the wrapper tries to register the new VM, as the Manager is telling the VirtualBox hypervisor that a VM with the same name is already registered).

So if you have not yet upgraded to VirtualBox 4.1 or later, we recommend you do not have the VirtualBox Manager window open when T4T runs.

If you are experiencing these problems, please abort the running WU, then stop BOINC. Open the VirtualBox Manager, check that the BOINC_VM has been completely removed (check also that the virtual hard disk cernvm.vmdk has been removed from the Media Manager) and then close the Manager. Then, run BOINC again and try to not run the Manager and BOINC together from this point.

If you are still experiencing problems, go to the message boards and ask for more help.

First of all, HAVE YOU INSTALLED VirtualBox ??

Next, check that your BOINC installation sets up the correct permissions for running VirtualBox (this applies to Linux and MacOSX systems, not Windows). Recheck our information on "Installing BOINC".

If BOINC is correctly installed, the main reason for that message is that the wrapper fails to remove an old virtual machine (VM) after it has expired, and so cannot register a new VM for the next Work Unit (WU). This is due to VirtualBox bugs, especially in Windows 64 bit systems. The cure is to upgrade VirtualBox to 4.1 level or later.

The best solution for cleaning your project files if you have to do it manually is:

1. Abort the running WU.
2. Quit BOINC (the core client should be not running).
3. Open VirtualBox Manager, remove the registered BOINC_VM virtual machines.
4. Open VirtualBox Media Manager and remove the cernvm.vmdk virtual hard disk if it is registered.
5. Launch BOINC again.

If after following those steps (and upgrading to VirtualBox 4.1 or later) you get the same error, please look at the FAQ entry: The next WU is failing and the previous one was running OK. What could be wrong?

If the BOINC_VM virtual machine does not respond at all to BOINC (i.e. you quit BOINC but the VM is still running) you can try the following steps to recover the project:

1. Open a command line terminal window on your system and run the command:
   1. VBoxManage controlvm BOINC_VM savestate
   2. If the VM is stopped and saved, then you can restart BOINC and T4T should work normally again. Otherwise you will have to check the following step:
2. If the VM does not respond to the above VBoxManage command you will have to forcibly quit the VM process: first you will have to:
   1. Abort the running WU and exit BOINC. Then, you will have to manually kill or quit the VirtualBox process. It will be different in each operating system, but usually:
      1. In Windows: open the Windows task manager and kill the VirtualBox process.
      2. In GNU/Linux: you can kill the VirtualBox process using your Desktop manager or from a terminal using the kill -9 command to kill the PID of the process called "VirtualBoxVM".
      3. In Mac OS X: you can kill it using the Terminal interface and running the kill -9 command to kill the PID of the process called "VirtualBoxVM".
   2. Restart BOINC: it should receive a new clean WU and everything should be working OK again. If at this point you are still having problems, please use the message boards to get more help.

If after quitting BOINC, the virtual machine continues running, you can safely stop it by running the following command in your computer:

VBoxManage controlvm BOINC_VM savestate

VirtualBox warns the user about how the keyboard and mouse will be captured if you click inside the window of the virtual machine. This message will pop up everytime you run a virtual machine unless you tick the "don't show this window again" option in the message box.

When you click inside the window of the Virtual Machine, the keyboard and mouse are grabbed by the virtual machine. If you want to release them, you have to press the Host Key (Right Ctrl) or (Right Cmd in Mac OS X). You can check which is the Host Key by clicking in: File->Preferences->Input

You have a full description of how you can debug the project here. Additionally, the source code of the wrapper is publicly available in the Github Code Repository or in the official BOINC one.

If you have found an error or a bug in the application, the experiments, the project, etc. please write a post about the error in the message boards so the T4T administrators and volunteers can participate in solving the problem.

Additionally you can use the Issues section of the Github Code Repository of the "boincvm" project to report it.

BOINC must not be installed as a service (Windows) or a daemon (GNU/Linux and Mac OS X) because this project uses Virtual Machines. When BOINC is installed as a service or a daemon it runs as an unprivileged user and cannot run any virtual machine.

The best solution to solve this problem under Windows is to install BOINC disabling the Service option in the Windows installer. For Mac OS X users you have to run a specific script that we have created, and for GNU/Linux users the recommendation is to use the official BOINC GNU/Linux installer instead of the packaged ones for your distribution.

If you have installed BOINC with the Protected Application Execution option enabled, then you will not be able to run the project, and all the work units will fail. The reason is that when you install BOINC with that flag enabled, BOINC is run under an unprivileged user that cannot create, start, pause, resume virtual machines at all. Thus, the wrapper will not be able to run the required virtual machine of this project.

In order to solve it, please, reinstall BOINC with that option disabled.

You can change how much CPU time is used by the Virtual Machine going into your account and changing the Preferences for this project -> Maximum CPU % for Virtual Machine. You can specify an amount between 0 and 100% (by default 100%), the save it and restart BOINC.

This project uses the following ports:

• Jabber messaging which needs XMPP (port 5222),
• Chirp (port 9094) for moving data in and out, and
• HTTP (port 80).

No other ports are used by the project.

LHC@home 2.0 is under heavy testing, and from time to time we will find a bug and its fix may require us to cancel all the running WUs on the computers. If this happens to you, check the news message board, as a new VirtualBox virtual machine (or a wrapper) may have been released with an update or patch. If you don't find any clue in the message boards, open a thread and ask for help.

If you only have access to Internet via a Proxy, you may get Compute Errors in BOINC, as the Virtual Machine needs direct connection to Internet. For the moment there is no solution, but we will try to fix it.

In order to run a multi-core virtual machine, VirtualBox needs a set of specific chip extensions usually enabled by default in recent computers and laptops. However, some vendors disable these extensions in the BIOS configuration, so you will not be able to run a Virtual Machine with two or more cores.

WARNING: CHANGING THE CONFIGURATION OF THE BIOS COULD BE DANGEROUS!!!!

DO NOT MODIFY IT UNLESS YOU KNOW WHAT YOU ARE DOING!!

If you want to solve it you will have to access the BIOS settings of your computer. Our recommendation is to read the manuals of your computer and check if there is a clear solution to enable this feature in your computer as every computer has a different set up for the BIOS settings. However, remember that this operation could be dangerous for your system if you modify something different than the virtualization extensions. If you do not feel comfortable modifying the BIOS settings, let the VM run with one core, as the wrapper should detect the problem and run with just one core.

Yes, you can. Please, go to your profile account in the Test4Theory web server. Then modify the project preferences by changing the value of the following field: Run Virtual Machine in headless mode: no to yes.

The web application provided in the virtual machine uses JavaScript, HTML5 and CSS3 to show the results and your BOINC credit using technologies like JavaScript, JSON and HTML5.

If you cannot enable JavaScript in your browser's settings or your browser does not support HTML5 and/or CSS3, you will be missing a friendly user interface to the results:

• an interactive gallery with all the figures from the simulations of your computer:
  • zoom in and out with a friendly interface,
  • browse the figures (next,previous and index) using shortcuts and without going back and forward to see other image,
  • swipe movement for flicking through images on touch devices,
  • etc.
• and some BOINC statistics.

Here you have an screenshot of the web page with a free, modern and open source web browser like Mozilla Firefox or Google Chrome:

You can still access the raw figures and BOINC stats data and the LOGs folder as you will get a warning with links to those resources.

If you get that error it seems like your installation processed missed the installation of the vboxdrv.inf driver. Please, first try to reinstall VirtualBox if this does not solve the problem, go to C:\Program Files\Oracle\VirtualBox\Drivers\ and double click in the file vboxdrv.inf. After that, you should be able to run VirtualBox without problems.

Virtualization, in computing, is the creation of a virtual computer that can run an operating system, applications, etc. within your real hardware. You can obtain more information about this topic in the Wikipedia.

This project runs very large CERN software packages with complex dependencies that cannot be easily ported to all the volunteers' operating systems (Windows, GNU/Linux and Mac OS X). For this reason, we use a virtualization solution, which enables us to run complex codes independently of your platform. Additionally, using virtualization adds an extra layer of security, as if something goes wrong in the code execution this will not affect your computer.

VirtualBox is a powerful x86 and AMD64/Intel64 virtualization product for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers, it is also the only professional solution that is freely available as Open Source Software under the terms of the GNU General Public License (GPL) version 2.

CernVM is a Virtual Software Appliance for the participants of CERN LHC experiments. The Appliance represents an extensible, portable and easy to configure user environment for developing and running LHC physics software both locally, on Grids and on Clouds, independently of Operating System software and hardware platforms (GNU/Linux, Windows, MacOSX).

The goal is to remove a need for the installation of the experiment software on each target platform, and thus to minimize the number of platforms (compiler-OS combinations) on which experiment software needs to be supported and tested. Visit the homepage for further details.

Our latest wrapper finally supports your multi-core system. However, we are not using at most two cores, because the experiments will not benefit at all from 3 or more cores. Thanks to this, your BOINC client will be able to run other projects in the free and available cores of your computer.

The Co-Pilot software detects if your virtual machine is in an unrecoverable state (due to unexpected errors, lost of connectivity, etc.), and reboots/resets it to start the execution of new experiments again. This will not affect at all your work unit or BOINC credit.